When working with Citrix, it may become necessary to modify or disable the Citrix ICA client hotkey mappings to allow a program to function properly. For example, suppose that you have a program that requires the use of the F1 function key. To allow the program on the Citrix server to recieve this keypress, you must disable the Citrix ICA client from interpreting the F1 keypress as a Citrix ICA function.
It is possible to change these settings via a GUI if the Program Neighborhood Agent is installed. However if you are using just the Online Plug-In, you will need to find these registry entries and change them.
You find the entries here:
[HKEY_LOCAL_MACHINE\SOFTWARE\Citrix\ICA Client\Engine\Configuration\Advanced\Modules\Hotkey Keys]
Find the function key you would like to disable, change the value to zero and your set. Reboot the client PC (or reload the ICA Client) and your hosted app should now accept the desired function key properly.