Error handling is an important part of creating web applications and espesially in drupal development. There are three different error handling methods: 

        * Simple "die()" statements
        * Custom errors and error triggers
        * Error reporting

    It’s quite simple to create a custom error handler. Just create a special function that can be called when an error occurs in PHP. 
 

error_function(error_level,error_message,
 
error_file,error_line,error_context)

A function to handle errors is shown below:

function customError($errno, $errstr)
 
  {
 
  echo "Error: [$errno] $errstr
";
 
  echo "Ending Script";
 
  die();
 
  }