// GPA CALCULATOR

function setFocus() {
        document.GPA.CGPA.focus();
        return;
}


function compute(obj) { 
if (obj.TTD.value=="0" && obj.cach.selectedIndex=="0" &&
obj.cbch.selectedIndex=="0" && obj.ccch.selectedIndex=="0" &&
obj.cdch.selectedIndex=="0" && obj.cech.selectedIndex=="0" && obj.cech.selectedIndex=="0" )    
{alert ("You must enter credit hours in at least one place") } 
else
{obj.result.value
=(eval(obj.TTD.value)*eval(obj.CGPA.value)+
eval(obj.cach.selectedIndex)*eval(obj.cagr.selectedIndex)+
eval(obj.cbch.selectedIndex)*eval(obj.cbgr.selectedIndex)+
eval(obj.ccch.selectedIndex)*eval(obj.ccgr.selectedIndex)+
eval(obj.cdch.selectedIndex)*eval(obj.cdgr.selectedIndex)+
eval(obj.cech.selectedIndex)*eval(obj.cegr.selectedIndex)+
eval(obj.cfch.selectedIndex)*eval(obj.cfgr.selectedIndex))
/(eval(obj.TTD.value)+eval(obj.cach.selectedIndex)+
eval(obj.cbch.selectedIndex)+eval(obj.ccch.selectedIndex)+
eval(obj.cdch.selectedIndex)+eval(obj.cech.selectedIndex)+eval(obj.cfch.selectedIndex))
}
}
function compute2(obj){
if (obj.CGPA3.value<= obj.CGPA.value)
{alert ("your desired grade has to be higher than your current standing")}
else
 if (obj.PGPA.value<=obj.CGPA3.value || obj.PGPA.value>4)
{alert ("Your predicted performance has to be better than your cumalitive desired performance and less than 4")} 
else
{obj.result2.value=Math.ceil(eval((eval(obj.CGPA3.value)-eval(obj.CGPA.value))*eval(obj.TTD.value/
(eval(obj.PGPA.value)-eval(obj.CGPA3.value)))))+" hours"}
}
function compute3(obj){
if (obj.CGPA3B.value>4)
{alert ("your desired grade can't be greater than 4.0")}
else
 if (obj.PGPAB.value>20)
{alert ("Twenty hours is the maximum load")} 
else
{obj.result3.value=eval(obj.CGPA3B.value)+(eval(obj.CGPA3B.value)-eval(obj.CGPA.value))*eval(obj.TTD.value)/eval(obj.PGPAB.value)}
}


function round2d(n)
{
 return(Math.round(100*n)/100);
}

function gpacalc()
{
//define valid grades and their values
var gr = new Array(); 
var cr = new Array();
var ingr = new Array();
var incr = new Array();

// define valid grades and their values
var grcount = 26; 
gr[1] = "A"; 
cr[1] = 4; 
gr[2] = "A-";
cr[2] = 3.70;
gr[3] = "B+";
cr[3] = 3.30;
gr[4] = "B";
cr[4] = 3;
gr[5] = "B-";
cr[5] = 2.70;
gr[6] = "C+";
cr[6] = 2.33;
gr[7] = "C";
cr[7] = 2;
gr[8] = "C-"
cr[8] = 1.67
gr[9] = "D+";
cr[9] = 1.33;
gr[10] = "D";
cr[10] = 1;
gr[11] = "D-";
cr[11] = 0.67;
gr[12] = "F";
cr[12] = 0;
//For lower case letters
gr[13]  = "a";
cr[13] = 4; 
gr[14] = "a-";
cr[14] = 3.70;
gr[15] = "b+";
cr[15] = 3.30;
gr[16] = "b";
cr[16] = 3;
gr[17] = "b-";
cr[17] = 2.70;
gr[18] = "c+";
cr[18] = 2.33;
gr[19] = "c";
cr[19] = 2;
gr[20] = "c-"
cr[20] = 1.67
gr[21] = "d+";
cr[21] = 1.33;
gr[22] = "d";
cr[22] = 1;
gr[23] = "d-";
cr[23] = 0.67;
gr[24] = "f";
cr[24] = 0;

// retrieve user input

ingr[0] = document.GPACalcForm.GR1.value;
ingr[1] = document.GPACalcForm.GR2.value;
ingr[2] = document.GPACalcForm.GR3.value;
ingr[3] = document.GPACalcForm.GR4.value;
ingr[4] = document.GPACalcForm.GR5.value;
ingr[5] = document.GPACalcForm.GR6.value;
incr[0] = document.GPACalcForm.CR1.value;
incr[1] = document.GPACalcForm.CR2.value;
incr[2] = document.GPACalcForm.CR3.value;
incr[3] = document.GPACalcForm.CR4.value;
incr[4] = document.GPACalcForm.CR5.value;
incr[5] = document.GPACalcForm.CR6.value;

// Calculate GPA

var allgr =0;
var allcr = 0;
var gpa = 0;
var resultcurgpa = 0;
for (var x = 0; x < 6; x++)
        {
        if (ingr[x] == "") 
        break;
//      if (isNaN(parseInt(incr[x]))) alert("Error- You did not enter a numeric credits value for Class If the class is worth 0 credits then enter the number 0 in the field."); 
        var validgrcheck = 0;
        for (var xx = 0; xx < grcount; xx++)
                {
                if (ingr[x] == gr[xx])
                        {
                        allgr = allgr + (parseInt(incr[x],10) * cr[xx]);
                        allcr = allcr + parseInt(incr[x],10);
                        validgrcheck = 1;
                        break;
                        }
                }
        if (validgrcheck == 0)
                {
                alert("Error- Could not recognize the grade entered for Class " + eval(x + 1) + ". Please use standard college grades in the form of a a- b+ ...f.");
                return 0;
                }
        }

// this if-check prevents a divide by zero error
if (allcr == 0)
    {
       alert("Error- You did not enter any credit values! GPA = N/A");
       return 0;
    }

gpa = round2d(allgr / allcr);
resultcurgpa = eval(gpa);
document.GPACalcForm.resultcurgpa.value = resultcurgpa;
return 0;
}

function cumCalc()
{
//define valid grades and their values
var gr = new Array(); 
var cr = new Array();
var ingr = new Array();
var incr = new Array();

// define valid grades and their values
var grcount = 26; 
gr[1] = "A"; 
cr[1] = 4; 
gr[2] = "A-";
cr[2] = 3.70;
gr[3] = "B+";
cr[3] = 3.30;
gr[4] = "B";
cr[4] = 3;
gr[5] = "B-";
cr[5] = 2.70;
gr[6] = "C+";
cr[6] = 2.33;
gr[7] = "C";
cr[7] = 2;
gr[8] = "C-"
cr[8] = 1.67
gr[9] = "D+";
cr[9] = 1.33;
gr[10] = "D";
cr[10] = 1;
gr[11] = "D-";
cr[11] = 0.67;
gr[12] = "F";
cr[12] = 0;

gr[13]  = "a";
cr[13] = 4; 
gr[14] = "a-";
cr[14] = 3.70;
gr[15] = "b+";
cr[15] = 3.30;
gr[16] = "b";
cr[16] = 3;
gr[17] = "b-";
cr[17] = 2.70;
gr[18] = "c+";
cr[18] = 2.33;
gr[19] = "c";
cr[19] = 2;
gr[20] = "c-"
cr[20] = 1.67
gr[21] = "d+";
cr[21] = 1.33;
gr[22] = "d";
cr[22] = 1;
gr[23] = "d-";
cr[23] = 0.67;
gr[24] = "f";
cr[24] = 0;
// retrieve user input
ingr[0] = document.GPACalcForm.GR1.value;
ingr[1] = document.GPACalcForm.GR2.value;
ingr[2] = document.GPACalcForm.GR3.value;
ingr[3] = document.GPACalcForm.GR4.value;
ingr[4] = document.GPACalcForm.GR5.value;
ingr[5] = document.GPACalcForm.GR6.value;
incr[0] = document.GPACalcForm.CR1.value;
incr[1] = document.GPACalcForm.CR2.value;
incr[2] = document.GPACalcForm.CR3.value;
incr[3] = document.GPACalcForm.CR4.value;
incr[4] = document.GPACalcForm.CR5.value;
incr[5] = document.GPACalcForm.CR6.value;

// Calculate GPA
var allgr =0;
var allcr = 0;
var gpa = 0;
for (var x = 0; x < 6; x++)
        {
        if (ingr[x] == "") break;
//      if (isNaN(parseInt(incr[x]))) alert("Error- You did not enter a numeric credits value for Class If the class is worth 0 credits then enter the number 0 in the field."); 
        var validgrcheck = 0;
        for (var xx = 0; xx < grcount; xx++)
                {
                if (ingr[x] == gr[xx])
                        {
                        allgr = allgr + (parseInt(incr[x],10) * cr[xx]);
                        allcr = allcr + parseInt(incr[x],10);
                        validgrcheck = 1;
                        break;
                        }
                }
        if (validgrcheck == 0)
                {
                alert("Error- Could not recognize the grade entered for Class " + eval(x + 1) + ". Please use standard college grades in the form of a a- b+ ...f.");
                return 0;
                }
        }

// this if-check prevents a divide by zero error
if (allcr == 0)
        {
        alert("Error- You did not enter any credit values! GPA = N/A");
        return 0;
        }

gpa = allgr / allcr;


// set variables
var cumGPAnum = 0;
var cumCredTotal = 0;

// retrieve user input
cumGPAnum = parseFloat(document.GPACalcForm.cumGPA.value);
cumCredTotal = parseFloat(document.GPACalcForm.cumCredits.value);

if (document.GPACalcForm.cumGPA.value == "") 
   {  alert("You need to enter your previous cumulative gpa in order to calculate your new one.");
            return 0;
   }
   if (document.GPACalcForm.cumCredits.value == "") 
   {  alert("You need to enter the total number of credits you earned prior to this semester.");
            return 0;
   }
   if (document.GPACalcForm.cumGPA.value == gpa) 
   {  if (confirm("Are you sure you are entering your previous cumulative GPA, and not your new semester GPA?" +
                  " Hit OK if your sure, otherwise hit Cancel to change your values."))
      {}
      else
            return 0;
   }

// find total points
var points = 0;
points = (cumGPAnum * cumCredTotal);

// Add semester values to cumulative
points = points + allgr;
var credits = 0;
credits = cumCredTotal + allcr;

// Calculate new cumulative gpa
var newCum = 0;
newCum = round2d(points / credits);
var resultcumgpa;
resultcumgpa = eval(newCum);
document.GPACalcForm.resultcumgpa.value = resultcumgpa;

return 0;
}

function validateForm(form) 
{
   if (form.cumGPA.value == "") 
   {  alert("You need to enter your previous cumulative gpa in order to calculate your new one.");
            return false;
   }
   if (form.cumCredits.value == "") 
   {  alert("You need to enter the total number of credits you earned prior to this semester.");
            return false;
   }
   if (form.cumGPA.value == form.gpa.value) 
   {  confirm("Are you sure you are entering your cumulative gpa, and not your new semester gpa?");
   }
   
  else 
   {  return true;
   }
}


//-->