function validatedetails(form){
 var errstr="";

if (form.username.value.length<1) {errstr="Email address required\n";}

    if(form.username.value.length>1){
      if(form.username.value.indexOf('@',0)==-1 || form.username.value.indexOf('.',0)==-1){errstr=errstr+"Valid Email Address required:\n";}
    }

if (form.username.value != form.confirmemail.value) {errstr=errstr+"Please retype your email address\n";}

if (form.findus.options.value=='-1') {errstr=errstr+"Please let us know how you found us:\n";}

  if(errstr!=""){alert(errstr);return false;}

}