Loadrunner if LR_Fail exclude from write to file

Okay so I am attempting to create a utility script that will generate a bunch of users for my testing purposes. If the script passes I need the output to write to a file. Like this

At the end of the script action, if the transaction -

 lr_end_transaction("Util_02_MemberReg_04_Step2", LR_AUTO); 

is a pass, then move to the

lr_output_message("Writing to file = %s", filename);

However this is working I need it to exclude any transaction that is an LR_Fail. Right now it is write to my file if it passes or fails.

What I need to know is if there is a way to exclude LR_Fail from the write to command?

Thanks for you help.