function checnum(as)
{
	var dd = as.value;

	if(dd.lastIndexOf(' ')>=0){
	  dd = dd.replace(' ','');
	  as.value = dd;
	}
	
	if(isNaN(dd))
	{
		dd = dd.substring(0,(dd.length-1));
		as.value = dd;
	}		
}

var x=1;
function add()
{
 	var s = document.getElementById('a').getElementsByTagName("TBODY")[0];
 	var trow = document.createElement("tr");
 	var tcol1 = document.createElement("td");
 	var tcol2 = document.createElement("td");
	
	var d = document.createElement("input");
	d.setAttribute('type','text');
	d.setAttribute('size','10');
	d.setAttribute('name','valu'+x);
	d.setAttribute('onkeyup','checnum(this)');
	d.style.backgroundColor= "#ffffff";
	d.style.border="1px #009bff solid";
	d.style.color = "#000000";
	d.style.fontWeight = "bold";

	var e = document.createElement("input");
	e.setAttribute('type','text');
	e.setAttribute('size','10');
	e.setAttribute('name','freq'+x);
	e.setAttribute('onkeyup','checnum(this)');
	e.style.backgroundColor= "#ffffff";
	e.style.border="1px #009bff solid";
	e.style.color = "#000000";
	e.style.fontWeight = "bold";


	tcol1.appendChild(d);
	tcol2.appendChild(e);
	trow.appendChild(tcol1);
	trow.appendChild(tcol2);
	s.appendChild(trow);

x++;
}

function del()
	{
		if(x>1){
			var len = x.length;
			var s = document.getElementById('a').getElementsByTagName("TBODY")[0];
			//alert(t.childNodes.length);
			s.removeChild(s.lastChild);
			x=x-1;		
		}
	}

function calculate()
{
	//alert(x);

	var xx=0;
	var yy=0;
	var zz;
	
 	for(var y=0; y<x; y++)
 	{

		var xxx = document.getElementById('a').getElementsByTagName("TBODY")[0];

		//var a = eval("document.first.valu"+y).value;		
		var a = xxx.getElementsByTagName("input").item(y*2).value;
		//var b = eval("document.first.freq"+y).value;
		var b = xxx.getElementsByTagName("input").item(1+y*2).value;
		//alert(a+"  "+b);
		xx = xx+(a*b);
		yy = yy+parseInt(b);
	}
	zz = xx/yy;
	var tot = (xx+"/"+yy);
	//alert(xx);
	var zz1 = Math.round(zz*100000)/100000;
	document.first.r1.value = tot;
	document.first.r2.value = zz1;	

}




function color(test)
{

	for(var j=2; j<10; j++)
	{
		var myI=document.getElementsByTagName("input").item(j);
		//myI.setAttribute("style",ch);
		myI.style.backgroundColor=test;
	}
}


function color1(test)
{
var myI=document.getElementsByTagName("table").item(0);
//myI.setAttribute("style",ch);
myI.style.backgroundColor=test;
}