minussign="–"
sdigits=" 0123456789"

function rand(n){return Math.floor(Math.random()*n)}

function setsubs(sform,icharge)
{
	var s=""
	var sf=""
	for (var i=0;i<sform.length;i++)
	{
		s=sform.charAt(i)
		sf=sf + (sdigits.indexOf(s)>0?"<sub>"+s+"</sub>":s)
	}
	//# 630
	if(icharge)sf+="<sup>"
	+(icharge==1 || icharge==-1?"":Math.abs(icharge))
	+(icharge>0?"+":minussign)
	+"</sup>"
	return sf
}


function roundoff(x,ndec)
//# 190
{
	//round x to ndec decimal places
	if(ndec==0)return Math.round(x)+""
	var xstring=x+" "
	var i=xstring.indexOf("E")
	if(i>0) return x
	i=xstring.indexOf("e")
	if(i>0) return x
	i=xstring.indexOf(".")
	//# 200
	if(i<0)
	{
		xstring=x+"."+"00000"+" "
		i=xstring.indexOf(".")
	}
	if(ndec==0)
	{
		xstring=xstring.substring(0,i)
	}else{
		//# 210
		xstring=xstring.substring(0,i)+"."+xstring.substring(i+1,i+1+ndec)
	}
	if(i==0) xstring="0"+xstring
	if(xstring.indexOf("-.")==0)xstring="-0"+xstring.substring(1,xstring.length)
	if(xstring=="-")xstring="0"
	return xstring
}