Handling Error in PHP Coding

Is there anyone can help on how to handle Error in PHP? Instead of displaying this error below:
Warning: fopen(welcome.txt) [function.fopen]: failed to open stream:
No such file or directory in C:webfoldertest.php on line 2
I want it to display a sentence that there is an error for example “Error found” or “File not Found” instead of the Error displayed above.
