Digital Routes: 2005 Programming Challenge

Problem:

Write a web-based application with a form field where one can type in an expression. The application will check the expression and report whether the brackets match.

Examples of valid expressions:

a + (b - (c) / d)
(()(())())()

Examples of invalid expressions:

a + (b - (c / d)
(()))(()
:-)

You have been provided with a username and password which grants SSH access to our server. You can use any programming language you wish, as long as there is an open source version. All the usual languages are available (Python, Perl, PHP, Euphoria, C, C++, shell, Ruby, etc) and installed. Installing new programming environments is perfectly acceptable.

This is a relatively simple challenge. What we are looking for is how you extend it, modify it, or put your own personality into it. Have fun with it. Don't be afraid to do something unusual or to bend the specification. Programming is fun, and we hope you enjoy this.