var prob = new Array(6)
prob[1]="\\sin("
prob[2]="\\cos("
prob[3]="e^{"
prob[4]="\\ln("
prob[5]="\\tan^{-1}("
prob[6]="\\sin^{-1}("
var aVar = 3
var bVar = 5
var cVar = 3
var dVar = 2
var step = 0
var poly = "\\int\\,(3x+2)\\,e^{5x}\\,dx"
var string1 = "Test"
var string2
var string3
var string4
var string5
var string6
var string1a
var string2a
var string3a
var string4a
var endString ="\\end{array}"

function writeNewEqn(){
   with(Math){
     aVar = round(5*random()+1)
     bVar = 0
     while(bVar==0){
      bVar = round(18*random()-9)
     }
     cVar = 0
     while(cVar==0){
      cVar = round(18*random()-9)
     }
     dVar = round(8*random()+1)
   }
   if((aVar!=3)&&(aVar!=6)){
    poly="\\int\\,("+cVar+"x + "+dVar+")\\,"+prob[aVar]+bVar+"x)\\,dx\\\\"
   } else {
   if(aVar==3){
    poly="\\int\\,("+cVar+"x + "+dVar+")\\,"+prob[aVar]+bVar+"x}\\,dx\\\\"
   } else {
    poly="\\int\\,"+cVar+"\\,"+prob[aVar]+bVar+"x)\\,dx\\\\"
   }}
   document.polynomial.reloadFromTeXString('$$'+poly+'$$');
   document.eq1.reloadFromTeXString('$$ $$')
   document.eq2.reloadFromTeXString('$$ $$')
   document.eq3.reloadFromTeXString('$$ $$')
   document.eq4.reloadFromTeXString('$$ $$')
   document.eq5.reloadFromTeXString('$$ $$')
   document.derivative.Continue.value="Continue"
   document.derivative.Cont1.value="Continue"
   document.derivative.Cont2.value="Continue"
   step=0
}
function writeEqn(){
   string1a = cVar+"x +"+dVar
   if((aVar==1)||(aVar==2)){
      string2a = prob[aVar]+bVar+"x)\\,dx"
   } else { if(aVar==3){
      string2a = prob[aVar]+bVar+"x}\\,dx"
   } else { if(aVar==6){
      string1a = prob[aVar]+bVar+"x)"
      string2a = cVar+"\\,dx"
   } else {
      string1a = prob[aVar]+bVar+"x)"
      string2a = cVar+"x +"+dVar+"\\,dx"
   }}}
   string1 = "u\\,=\\,"+string1a
   string2 = "dv\\, =\\,"+string2a
   document.eq1.reloadFromTeXString('$$'+string1+'$$')
   document.eq2.reloadFromTeXString('$$'+string2+'$$')
   document.derivative.Continue.value="Go to next step."
}
function writeEqn1(){
   string3a = cVar+"\\,dx"
   string3c=""
   if(aVar==1){
      string4b = "\\int\\,"+prob[aVar]+bVar+"x)\\,dx\\,=\\,"
      string4a = "\\frac{-1}{"+bVar+"}\\cos("+bVar+"x)"
   } else { if(aVar==2){
      string4b = "\\int\\,"+prob[aVar]+bVar+"x)\\,dx\\,=\\,"
      string4a = "\\frac{1}{"+bVar+"}\\sin("+bVar+"x)"
   } else { if(aVar==3){
      string4b = "\\int\\,"+prob[aVar]+bVar+"x}\\,dx\\,=\\,"
      string4a = "\\frac{1}{"+bVar+"}e^{"+bVar+"x}"
   } else {
      string4b = "\\int"+cVar+"x +"+dVar+"\\,dx\\,=\\,"
      string4a = "\\frac{"+cVar+"}{2}x^2+"+dVar+"x"
      if(aVar==4){
       string3c = "\\frac{1}{"+bVar+"x}\\cdot"+bVar+"\\,dx\\,=\\,"
       string3a = "\\frac{1}{x}\\,dx"
      } else {
      if(aVar==5){
       string3a = "\\frac{1}{1+("+bVar+"x)^2}\\cdot"+bVar+"\\,dx"
      } else {
       string3a = "\\frac{1}{\\sqrt{1-("+bVar+"x)^2}}\\cdot"+bVar+"\\,dx"
       string4b = "\\int"+cVar+"\\,dx\\,=\\,"
       string4a = cVar+"x"
      }}
   }}}
   string3 = "du\\,=\\,"+string3c+string3a
   string4 = "v\\, =\\,"+string4b+string4a
   document.derivative.Cont1.value="Go to next step."
}
function writeEqn2(){
   if(step==0){
     string5="\\begin{array}{l}"+poly+"\\\\"
     string5=string5+"=\\,\\left["+string1a+"\\right]\\cdot\\left["+string4a+"\\right]\\,-\\int\\,\\left["+string4a+"\\right]\\cdot"+string3a+"\\\\"
     step=1
   } else {
   if(step==1){
     string5=string5+"=\\,\\left["+string1a+"\\right]\\cdot\\left["+string4a+"\\right]\\,"
     if(aVar==1){
       string5=string5+"+\\,\\frac{"+cVar+"}{"+bVar*bVar+"}\\,\\sin("+bVar+"x)\\,+C"
       document.derivative.Cont2.value="Done!"
     } else {
     if(aVar==2){ 
       string5=string5+"-\\,\\frac{"+cVar+"}{"+bVar*bVar+"}\\,\\cos("+bVar+"x)\\,+C"
       document.derivative.Cont2.value="Done!"
     } else {
     if(aVar==3){
       string5=string5+"-\\,\\frac{"+cVar+"}{"+bVar*bVar+"}\\,e^{"+bVar+"x}\\,+C"
       document.derivative.Cont2.value="Done!"
     } else {
     if(aVar==4){
       string5=string5+"-\\,\\int\\,\\frac{"+cVar+"}{2}x+"+dVar+"\\,dx\\\\"
     } else {
     if(aVar==5){
       string5=string5+"-\\,\\int\\,\\frac{"+cVar+"}{"+2*bVar+"}\\,+\\,\\frac{"+dVar*bVar+"x}{1+"+bVar*bVar+"x^2}\\,-\\,\\frac{"+cVar+"}{"+2*bVar+"}\\,\\frac{1}{1+"+bVar*bVar+"x^2}\\,dx\\\\"
     } else {
     if(cVar*bVar<0){
       string5=string5+"+\\,"+(-cVar)*bVar+"\\int\\,\\frac{x}{\\sqrt{1-("+bVar+"x)^2}}\\,dx\\\\"
     } else {
       string5=string5+"-\\,"+cVar*bVar+"\\int\\,\\frac{x}{\\sqrt{1-("+bVar+"x)^2}}\\,dx\\\\"
     }}}}}}
     step=2
   } else {
   if(step==2){
     if(aVar>3){
       string5=string5+"=\\,\\left["+string1a+"\\right]\\cdot\\left["+string4a+"\\right]\\,"
     }
     if(aVar==4){
       string5=string5+"-\\,\\frac{"+cVar+"}{4}x^2-"+dVar+"x +C\\\\"
     }
     if(aVar==5){
       string5=string5+"-\\,\\frac{"+cVar+"x}{"+(2*bVar)+"}\\,-\\,\\frac{"+dVar+"}{"+2*bVar+"}\\ln(1+"+bVar*bVar+"x^2)\\,+\\,\\frac{"+cVar+"}{"+2*bVar*bVar+"}\\,\\tan^{-1}("+bVar+"x)+ C\\\\"
     }
     if(aVar==6){
       if(cVar*bVar<0){
         string5=string5+"+\\,\\frac{"+cVar+"}{"+bVar+"}\\,\\sqrt{1-("+bVar+"x)^2}+C\\\\"
       } else {
         string5=string5+"-\\,\\frac{"+cVar+"}{"+(-bVar)+"}\\,\\sqrt{1-("+bVar+"x)^2}+C\\\\"
     }}
     document.derivative.Cont2.value="Done!"
     step=3
   }}}
   string6=string5+endString
   document.eq5.reloadFromTeXString('$$'+string6+'$$')
}