function contar(src,maximo){
	n = src.value.length;
	t = maximo;
	var id=src.name+"Restantes"
	document.getElementById(id).value=(t-n);
}

//var supportsKeys = true
function calcCharLeft(f,maximo) {
	lenUSig = document.getElementById(f.name+"lenSSig").value
	maxLength = maximo - document.getElementById(f.name+"lenSysSig").value - lenUSig
	if ( document.getElementById(f.name).value.length > maxLength) {
		document.getElementById(f.name).value = document.getElementById(f.name).value.substring(0,maxLength)
		charleft = 0
	} else {
		charleft = maxLength - document.getElementById(f.name).value.length
	}
	document.getElementById(f.name+"msgCL").value = charleft
}