FPM_OPEN_DIALOG Event is not populated in the Event Dropdown

Hi ,

I have created a Button on the Sap Toolbar and now want to assign the FPM_OPEN_DIALOG  event but cannot see this option for the button created on the Standard Sap toolbar screen .  Is there any specific interface needs to be added in the feeder class ?

However FPM_OPEN_DIALOG option is populated in the dropdown if I create a button on the GUIBB and then assign an event for it . I am clueless why it is not populated when the button is created in the standard sap toolbar .

Here is the screenshot :

Regards,

Vicky