function littleLawForm()
{
	var nVirtu;
	var thinkTime;
	var avgRes;
	var avgThru;
	
	//validation of Number of Virtual Users....it must be an integer>0
	nVirtu = document.littlelaw.nVirtu.value;
	if (nVirtu < 0 || isNaN(nVirtu) || (nVirtu==""))
	{
		alert("Enter a positive integer value");
		document.forms[0].elements[0].value = "";
		document.forms[0].elements[0].focus();
		return false;
	}
	
	for(i=0;i<nVirtu.length;i++)	//check whether input is an integer
	{
		var firstCh=nVirtu.charAt(i)
		if(firstCh<"0" || firstCh>"9")
		{
			alert("Enter an integer value");
			document.forms[0].elements[0].value = "";
			document.forms[0].elements[0].focus();
			return false;
		}
	}
	
	//validation of Constant Think Time
	thinkTime = document.littlelaw.thinkTime.value;
	if (thinkTime < 0 || isNaN(thinkTime) || (thinkTime==""))
	{
		alert("Enter a value for the constant think time");
		document.forms[0].elements[1].value = "";
		document.forms[0].elements[1].focus();
		return false;
	}
	
	//validation of Average Response Time
	avgRes = document.littlelaw.avgRes.value;
	if (avgRes < 0 || isNaN(avgRes) || (avgRes==""))
	{
		alert("Enter a value for the average response time");
		document.forms[0].elements[2].value = "";
		document.forms[0].elements[2].focus();
		return false;
	}
	
	//validation of Average Throughput
	avgThru = document.littlelaw.avgThru.value;
	if (avgThru < 0 || isNaN(avgThru) || (avgThru==""))
	{
		alert("Enter a value for the average throughput");
		document.forms[0].elements[3].value = "";
		document.forms[0].elements[3].focus();
		return false;
	}
	
	calcValue(nVirtu,thinkTime,avgRes,avgThru)
	
}

function calcValue(nVirtu,thinkTime,avgRes,avgThru)
{
	var result;
	
 
	result = (nVirtu - (avgThru * (parseFloat(avgRes) + parseFloat(thinkTime)))) / nVirtu ; 
    result = Math.abs(result);
    
	if (result <= 0.15)
	{
		document.getElementById('resVal').innerHTML= "<img src='correct.gif' style='border:0' alt='Passed' /> "; 
	}
	else
	{
		document.getElementById('resVal').innerHTML= "<img src='incorrect.gif' style='border:0' alt='Failed' /> ";
	}

}