F4 Help from Data Element

Hi Expert,

In my Table i am not getting f4 help for 2 attribute1st Date and 2nd Type of Expense i have created table and bind to Table column

1st Field --Date of type Dats .....I am not getting f4 help for this

2nd Field Type Of expense I have defined Data Element to field and binded to table column attribute ....

When i am testing application i am not getting f4 help for this field please let me knw how to do.

Regards,

Farooq