function checkData (){
	if (document.forms[0].visitor_name.value.length ==0){
		document.forms[0].visitor_name.focus();
		alert("Please enter your name.");
		return false;
	}
	if (document.forms[0].visitor_email_address.value.length ==0){
		document.forms[0].visitor_email_address.focus();
		alert("Please enter an e-mail address.");
		return false;
	}
	if (document.forms[0].visitor_email_address.value.length >0){
		i=document.forms[0].visitor_email_address.value.indexOf("@")
		j=document.forms[0].visitor_email_address.value.indexOf(".",i)
		k=document.forms[0].visitor_email_address.value.indexOf(",")
		kk=document.forms[0].visitor_email_address.value.indexOf(" ")
		jj=document.forms[0].visitor_email_address.value.lastIndexOf(".")+1
		len=document.forms[0].visitor_email_address.value.length
		if ((i>0) && (j>(1+1)) && (k==-1) && (kk==-1) && (len-jj >=2) && (len-jj<=3)) {
		} else {
			document.forms[0].visitor_email_address.focus()
			document.forms[0].visitor_email_address.select()
			alert("Please enter a valid email address.")
			return false
		}
	}
	if (document.forms[0].comments.value.length ==0){
		document.forms[0].comments.focus();
		alert("Please enter your comments or question.");
		return false;
	}
}