// JavaScript Document
function isNumeric(expression){
	var nums = "0123456789";
	if (expression.length==0)return(false);	
	for (var n=0; n < expression.length; n++)
	{
		if(nums.indexOf(expression.charAt(n))==-1)return(false);
	}
	return(true);
}

function cambiaColor(objeto, color){
	document.getElementById(objeto).style.backgroundColor = color
	return(true);
}