// Nomenclature - Organic Naming Script
pieces=new Array
thepage="Nomenclature - Organic Naming"
//refnumber=195
brkpt=0
totl=corrt=0
cstarts=new Array("H3C","H2C")
middles=new Array("CH2","CH","C")
theends=new Array("CH3","CH2","CH")
descript=thename=""
basename=new Array("none","meth","eth","prop","but","pent","hex","hept","oct")
alphaname=new Array(-10,4,1,7,0,6,3,2,5)
nameend=new Array("ane","ene","yne","yl")
thegroups=new Array("Cl","Br","I","NH2","OH","CHO","CO2H")
linkgroups=new Array("CO2","O","CO")
funcnames=new Array("chloro","bromo","iodo","amino","ol","al","oic acid")
linknames=new Array("ester","ether","ketone")
function cleanse(){
	totl=0
	corrt=0
	document.forms[0].total.value=totl
	document.forms[0].correct.value=corrt
	clear()
	}
function clear(){
	tried=0
	document.forms[0].results.value=""
	document.forms[0].theans.value=""
	clearansspot()
}
function startit(){
	totl++
	document.forms[0].total.value=totl
	clear()
	var f=0
	while(f<2)f=Math.ceil(8*Math.random())
	spot=Math.ceil((f-1)*Math.random())
	Math.random()<.5?dcount=1:dcount=0;
	descript=new Array(f,dcount,spot)
	Math.random()>.5?buildhcarbon():buildother()
}
function buildhcarbon(){
	//total length of the compound in carbons
	clength=descript[0];
	dcount=descript[1]
	dspot=descript[2]
	dcount>0 && dspot==1?cmpd=(cstarts[1]+"="):cmpd=cstarts[0]
	if(dcount==0){
		for(var j=1;j<(clength-1);j++)cmpd+=middles[0];
		cmpd+=theends[0]
	}
	else{
		for(var j=1;j<(clength-1);j++){
			if(j==(dspot-1)){
					cmpd+=middles[1]+"="
					}
			else{
				if(j==dspot+1)cmpd+=middles[1];
				else cmpd+=middles[0];
			}
		}
		dspot==(clength-1)?cmpd+=theends[1]:cmpd+=theends[0]
	}
	cmpd=getformula(cmpd)
	thename=""
	if(dcount==0)thename=basename[descript[0]]+nameend[0];
	else{
		dspot<=clength/2?dspot=dspot:dspot=clength-dspot;
		if(descript[0]>3)thename=dspot+"-";
		thename+=basename[descript[0]]+nameend[1];
		}
	thequest=cmpd+"<br>"+thename
	theanswer=thename
	showquest(cmpd)
}
function buildother(){
	Math.random()>.5?buildfgroup():buildlinked()
}
function buildfgroup(){
	dspot=Math.ceil(Math.random()*descript[0])
	clength=descript[0]
	cmpd=thename=""
	thegroup=Math.floor(Math.random()*thegroups.length)
	if(thegroup>4)dspot=clength;
	dspot==1?cmpd=("<b>"+thegroups[thegroup]+"</b>"+theends[1]):cmpd=cstarts[0]
	for(j=2;j<descript[0];j++){
		j!=dspot?cmpd+=middles[0]:cmpd+=(middles[1]+"<b>"+thegroups[thegroup]+"</b>")
	}
	if(thegroup>4)cmpd+="<b>"+thegroups[thegroup]+"</b>";
	else dspot==descript[0]?cmpd+=(theends[1]+"<b>"+thegroups[thegroup]+"</b>"):cmpd+=theends[0];
	cmpd=getformula(cmpd)
	//thename=basename[descript[0]]+nameend[0];
	dspot<=clength/2?dspot=dspot:dspot=clength-dspot+1;
	if(thegroup<=4){
		if(descript[0]>2 && thegroup<=4)thename=dspot+"-";
		if (thegroup<4)thename+=funcnames[thegroup]+basename[descript[0]]+nameend[0];
			else thename+=basename[descript[0]]+"anol"
		}
	else  thename+=(basename[descript[0]]+"an"+funcnames[thegroup]);
	thequest=cmpd+"<br>"+thename
	theanswer=thename
	showquest(cmpd)
}
function buildlinked(){
	first=Math.ceil(6*Math.random())
	second=Math.ceil(6*Math.random())
	lgroup=Math.floor(3*Math.random())
	first>1?sfirst=first:sfirst=""
	second>1?ssecond=second:ssecond=""
	cmpd="C"+sfirst+"H"+(2*first+1)+"<b>"+linkgroups[lgroup]+"</b>C"+ssecond+"H"+(2*second+1)
	cmpd=getformula(cmpd)
	thename=""
	if(first==second)thename="di"+basename[first]+"yl"+linknames[lgroup]
	else{
		if(lgroup==0){thename=basename[second]+"yl"+basename[first+1]+"anoate"}
		else{
		alphaname[first]<alphaname[second]?thename=basename[first]+"yl"+basename[second]+"yl"+linknames[lgroup]:thename=basename[second]+"yl"+basename[first]+"yl"+linknames[lgroup]
		}
	}
	thequest=cmpd+"<br>"+thename
	theanswer=thename
	showquest(cmpd)
}
		
function getformula(x){
		sdigits="z0123456789"
		sub="false"
		newstring=""
		thestring=x
		for(k=0;k<thestring.length;k++){
			nextchar=thestring.charAt(k)
			if(sdigits.indexOf(nextchar)>0){
				sub=="false"?newstring+=("<sub>"+nextchar):newstring+=nextchar;
				sub="true"
				}
			else{
				sub=="true"?newstring+=("</sub>"+nextchar):newstring+=nextchar;
				sub="false"
				}
		}
		sub=="true"?newstring+="</sub>":"";
		return newstring
}
function answer(ans){
	attempts++
	if(tried==1){alert("You've already done this problem. Get a new one!")}
	else{
	if(tried==2){totl++;document.forms[0].total.value=totl}
	if(ans==theanswer)
		{
    		document.forms[0].results.value="correct"
    		corrt++
    		document.forms[0].correct.value=corrt
    		tried=1
	}
	else{
    		tried=2
    		document.forms[0].results.value="incorrect"}
	}	
}