IF-Condition in WINSCP-Scripts

Hello all together
I use WINSCP since 2 Months and i have a problem with if Conditions.
I will download my works from a other Computer, this works well.
But Now i will download my files only if a specific file is on the other Computer.
How can I work with if conditions or what is the syntax of if conditions in WINSCP-Skripts.

Thank you for all informations.

Best Regards
Yousaint

Just try to download it and check if it succeeded or not.

Or see this example:
https://winscp.net/eng/docs/script_checking_file_existence