Note: This topic applies to Web (HTTP/HTML), Mobile Application - HTTP/HTML, Flex, and Web Services Vuser scripts.
After modifying a Vuser script to enable it to emulate asynchronous communication, it may be necessary to perform correlation activities on the modified script. Due to asynchronous nature, dynamic values from asynchronous communication cannot be handled by Design Studio, and must be correlated manually.
You can search for dynamic values inside Response callbacks functions using the lr_save_param_regexp function. This function can be called from a callback to extract the necessary value from server response (ResponseCB) or response buffer (ResponseBodyBufferCB), and assign this value to a parameter. This parameter can then be used for correlations.
For details about the lr_save_param_regexp function, see the Function Reference (Help > Function Reference).