function isblank(s) {
  for (var i=0; i < s.length; i++) {
    var b=s.charAt(i);
    if ((b != ' ') && (b != '\n') && (b != '')) return false;
  }
  return true;   
}   
// function to validate an email address
function ismail(mst) {
  var at=mst.indexOf("@");
  var dot=mst.lastIndexOf(".");
  var space=mst.indexOf(" ");
  var comma=mst.indexOf(",");
  if ((at!=-1) && (dot!=-1) && (dot > at+1) && (dot < mst.length-1) && (space== -1) && (comma== -1))
  {
   return true;}
   else {
   return false;}
}
// function to verify form
function verify(fm) {
  var msg="__________________________________________________\n\n";
      msg+="SORRY The form has not been submitted because:-" + "\n";
  var blank_fields="";
  for (var i=0; i < fm.length; i++) {
    var a=fm.elements[i];
    if ((a.type=="select-one") && (!a.optional)) {
      if (a.options[0].selected) {
         blank_fields += a.name;
         msg +="\n" + " ** The 'How Did You Find Us' field is invalid" + "\n";
         continue;
      }       
    } 
    if (((a.type=="text") || (a.type=="textarea")) && !a.optional) {
      if (a.name=="email_addr") {
        if (!ismail(a.value)) {
          blank_fields += a.name;
	  msg+="\n" + " ** The E-mail address is blank or invalid" + "\n";
          continue;
        }
      }            
      if ((a.value==null) || (a.value=="") || (isblank(a.value))) {
        blank_fields+=a.name; 
	  if (a.name=='real_name') 
	   {msg+="\n** The " + "Name" + " field is blank\n";}
		   else {if (a.name=='message') {msg+="\n** The Message field is blank\n";}
             else {msg+="\n** The " + a.name + " field is blank\n";}
	   } 
       } 
    }
  }	    
  if (!blank_fields) return true;
  
  msg+="\nPlease correct the details and resubmit.\n";
  msg+="__________________________________________________\n";
  alert(msg);
  return false;
}