function validate() {

    var f=document.regform;
    var msg="";
    var invalfocus;
    var reg = /^([\w-.]+)\@(([\w-])+\.)+([a-z]{2,4})$/i;
      
    if(!f.contact_name.value) {
	msg+="\n\tName";
	if(!invalfocus) invalfocus=f.contact_name;
    }
    if(!f.job.value) {
	msg+="\n\tJob Title";
	if(!invalfocus) invalfocus=f.job;
    }
    if(!f.company.value) {
	msg+="\n\tCompany";
	if(!invalfocus) invalfocus=f.company;
    }
    if(!reg.test(f.email.value)) {
	msg+="\n\tEmail (should be in a valid format, e.g. yourname@company.com)";
	if(!invalfocus) invalfocus=f.email;
    }
    if(invalfocus) {
	alert("Please complete the following fields before submitting the form:"+msg);
	invalfocus.focus();
	return false;
    }	
    
    return true;
}