function roll_over(img_name, img_src)
   {
   document[img_name].src = img_src;
   }
   
function check_form(form) {

  if (form.sug_name.value == ""){
    alert("Please enter your name.");
    form.sug_name.focus();
    return false;    
  }

  if (form.sug_email.value == ""){
    alert("Please enter your Email address.");
    form.sug_email.focus();
    return false;    
  }

  if (form.sug_email.value != ""){
    var emailat = "@";
    var emaildot = ".";
    var e_curr;
    var at = false;
    var dot = false;
    for (x = 0; x < form.sug_email.value.length; x++) {
      e_curr = form.sug_email.value.charAt(x);
      if (emailat.indexOf(e_curr) == 0){
        at = true;
      }
      if (emaildot.indexOf(e_curr) == 0){
        dot = true;
      }    
    }

    if ((at == false) || (dot == false)) {
      alert("Please enter a valid Email address");
      form.sug_email.focus();
      return false;  
    }
  } 
      
  if (form.suggestion.value == ""){
    alert("Please enter your Suggestion.");
    form.suggestion.focus();
    return false;    
  }   
  
  return true;
   

}