// contact form checking JavaScript Document
var whitespace=" \t\n\r";

function chkMailForm(f) {
	var b=chkMail(f.frome.value);
	if (!b) b=isNonWSL(f.fromc.value,4);
	if (!b) alert('Please enter a valid e-mail address or alternative contact information!');
	if (b) { b=isNonWSL(f.fromn.value, 6); if (!b) alert('Please enter your name!'); }
	if (b) { b=isNonWSL(f.msg.value, 10); if (!b) alert('Please enter a reasonable message!'); }
	return b;
}
function isNonWSL(t,l) { // true if string contains at least l non-whitespace characters
	var i,j=t.length,m=0;	for (i=0; i < j; i++) { if (whitespace.indexOf(t.charAt(i)) < 0) m++; if (m>= l) return true; }
	return false;
}
function chkMail(s) {
	var ptrn=/^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	return ptrn.test(s);
}