function validator(){

    var nameField =  document.forms["enrol_form"].name.value;
    var emailField =  document.forms["enrol_form"].email_address.value;
    var telephoneField =  document.forms["enrol_form"].telephone.value;

    if( nameField.length == 0 ){
      alert("Please enter your name!");
      return false;
    }

    if( telephoneField.length == 0 ){
      alert("Please enter your telephone number!");
      return false;
    }

    if( emailField.length == 0 ){
      alert("Please enter your email address!");
      return false;
    }

    document.forms["enrol_form"].submit();

  }//end validate


document.write('<form method="post" action="contact_us_process.asp" name="enrol_form"><div class="enrol_form">');
document.write('Your name:<br /><input type="text" name="name" /><br />');
document.write('Telephone number:<br /><input type="text" name="telephone" /><br />');
document.write('Email address:<br /><input type="text" name="email_address" /><br />');
document.write('Any comments?<br /><textarea cols="25" name="comments" style="height:112px;"></textarea><br />');
document.write('<br /><input type="button" value=" Submit " onclick="return validator();" />');
document.write('<br /><br /></div></form>');