function esVacio(campo)
{
	if (trim(campo) == '')
		{return true;}
	return false;
}

function trim( value ) {
	
	var re = /\s*((\S+\s*)*)/;
	var temp = value.replace(re, "$1");

	var re = /((\s*\S+)*)\s*/;
	return temp.replace(re, "$1");
	
}

function checkemail(str){
	var filter=/^.+@.+\..{2,4}$/;
	return (filter.test(str))
}

function esFecha(fecha){
	var regexp=/^(\d){1,2}[\/|\-](\d){1,2}[\/|\-](\d){2,4}/;
	return (regexp.test(fecha))
}