// SUMMARY
//
// This is a set of JavaScript functions for validating input on
// an HTML form.  Functions are provided to validate:

function validateString(txtField, label){
  if(isEmpty(txtField.value))
   { 
   	 alert('Please fill in: '+label.value);
	 return false;
   }
   else {return true;}
}

// Check whether string s is empty.

function isEmpty(s)
{   return ((s == null) || (s.length == 0))
}