how to monitor dynamic URLs

For Eg., If your login page has some hidden parameter that needs to be submitted while logging into your application and also the value for the hidden parameter is different for each login request. In this case, the hidden parameter value in the login page needs to be fetched dynamically and passed to the subsequent URL.

For monitoring these kind of dynamic URL Sequences, you can use $<Parameter name> in the Request Parameter text box of the URL. So, while monitoring the URL Sequence, $<Parameter name> will fetch the dynamic values and pass it to the next URL in the sequence.

Note: While using the Recorder tool, you cannot specify the parameters in the Request Parameter text box, so instead, after adding the URL Sequence, go to corresponding URL's 'Edit Monitor' and enter the parameters.

Also refer Forums - Example