function isnum(putativenumber,name,sign,zero,integer) //enter the variable to be checked,
//the name of the variable ('off', if you want no message displayed), and if desired, "plus" if it must be positive,  "no" if it can't be zero, and "yes" if it must be an integer.
{
	if (putativenumber.indexOf(",") != -1)
		{
		if (name!="off")
			{
			alert("Please do not use any commas (\",\") in "+name+".");
			}
		return (false);
		}
	if (isNaN(putativenumber) && putativenumber!=" ")
		{
		if (name!="off")
			{
			alert("Please enter only numbers for "+name+".");
			}
		return (false);
		}
	else if ((putativenumber < 0) && (sign=="plus"))
		{
		if (name!="off")
			{
			alert("Please enter only positive numbers for "+name+".");
			}
		return(false);
		}
	else if ((putativenumber ==0) && (zero=="no"))
		{
		if (name!="off")
			{
			alert("Please enter non-zero numbers for "+name+".");
			}
		return(false);
		}
	else if ((Math.floor(putativenumber)!=putativenumber) && (integer=="yes"))
		{
		if (name!="off")
			{
			alert("Please enter only integers for "+name+".");
			}
		return(false);
		}
	else 
		{
		return (true);
		}
}

function check(TheField)
{
	if (isnum(TheField,"off")&& TheField !="" && TheField!=" "){
		return (true);
		}
	else {
		return (false);
	}	
}

function getselectedbutton(buttongroup)
	{
	 for (var i=0; i <buttongroup.length;i++)
		{
		if (buttongroup[i].checked)
			{
			return buttongroup[i].value;
			break;
			}
		}
	alert("you must select a value from the radio buttons");
	return(false);
	}