How to reckon the response time required for something to change on a page..??

Hi,
I have an application which after a post request generates a report in PDF and CSV format which could be accessed afterwards. But my main question is that when a report is getting generated by the application, for some time, the label (in html… Generating… ) appears and after that it is hidden. Is there a possibility to calculate this time which is taken by the application to generate report…??
I used to do this easily in LR but am new to Gatling and cant figure that out.

ta,
Gaurav

BTW the Gatling version is: 2.1.7

Hi,
Can anybody help me out on the below scenario.
I will try to explain that again…
I have a long POST request comprising of more than 100 form parameters.
The response of this request is a Report which is generated in pdf or csv format****
Now, in the next request, I want to delete the generated report which again is a POST request.
My problem lies while the report is getting generated. Since one cannot delete the report till the UI/response is showing"**** Generating… " text. This text appears only till the report is in a limbo or is in a process of getting generated.
So my question is: Can somehow I put the execution on hold till this text disappears so that I could fire next POST request to delete the report which is generated.

ta,
Gaurav

I need the timespan for which the response of a previous POST request shows a html text(in html… Generating… ) before firing another http request so that the execution pauses for the said amount of time. Presently my previous request is not completed and hence I am unable to execute the next request.