Response.Clear

In some situations the script may need to "replace" the generated output because of some reason. For example this can be an error occurred somewhere in the middle of the processing. In that case you may want to show some error instead of the incomplete output.

Output fra MSDN:

The Clear method erases any buffered HTML output. However, the Clear method only erases the response body; it does not erase response headers. You can use this method to handle error cases. Note that this method will cause a run-time error if Response.Buffer has not been set to TRUE.