RegEx Master

Know Regular expressions really well, if you do, we have a job for you.

We need thousand of regular expressions written and will pay well for anyone that can write them quickly and correctly.

It doesn't matter if you know:
Regex, Ruby, PHP, Pythong, C#, Java etc, I just need a person that knows Regex as you will be provided strings of text and be asked to write regex patterns that extract that required data out of the strings.

Task:
We will provide you with a webpage url.
You will be required to write a regex pattern that extracts the required data from out of the string.

To Apply please respond with the answer:

Sample String:
http://www.drugstore.com/products/prod.asp?pid=386663&catid=283116

Provide me the regex that would return the below result no matter what i added to the end of the string.

Result:
http://www.drugstore.com/products/prod.asp?pid=386663