function BrowserCheck() 
{
	var b = navigator.appName
	if (b=="Netscape") this.b = "ns"
	else if (b=="Microsoft Internet Explorer") this.b = "ie"
	else this.b = b
	this.version = navigator.appVersion
	this.v = parseInt(this.version)
	this.ns = (this.b=="ns" && this.v>=4)
	this.ns4 = (this.b=="ns" && this.v==4)
	this.ns5 = (this.b=="ns" && this.v==5)
	this.ie = (this.b=="ie" && this.v>=4)
	this.ie4 = (this.version.indexOf('MSIE 4')>0)
	this.ie5 = (this.version.indexOf('MSIE 5')>0)
	this.min = (this.ns||this.ie)
}

is = new BrowserCheck();

function stripSpaces(xx) 
{ 
	x = new String(xx);
	while (x.substring(0,1) == ' ') 
		x = x.substring(1); 
	while (x.substring(x.length-1,x.length) == ' ') 
		x = x.substring(0,x.length-1); 
	return x;
}

function validarAmarillo(campo)
{
	var valor
	valor=stripSpaces(campo.value);
	if (!is.ns)
	{
		if (valor!=0)
			campo.style.backgroundColor="white";
		else
			campo.style.backgroundColor="#FFFFCC";
		return true;
	}
}