Error in user difined form -Form -Alredy Exist [66000-106]

Hi Experts ,

i have develop my screens through screen painter.

when i opn forms in sap as multiple time i have faced following errors:

*Form -Alredy Exist [66000-106]*

*The Choose From List unique ID already exists [66000-106]*

how can avoide this errors

please help me for this

Regards,

Pravin Baji