To Validate Numbers Using JavaScript

function Validatenumber(obj)
{
	if (obj.length !=0)
	{
		var text = /^[-0-9]+$/;
		if ((document.getElementById(obj.id).value!="")&&(!text.test(document.getElementById(obj.id).value)))
		{
			alert("Please enter numeric values only");
			obj.focus();
			obj.select();
		}
	}
}