change dropdown to plain text

[fauzianywhere]

How do I change the input data type from drop down to plain text if the undangan? column has the value N?

[WillowMobileSys]

You cannot dynamically change Column data types.   

Maybe what you mean is to switch from a choice on a dropdown to requiring a user typed response?  How you would go about this would be determined by how you have defined the "Nama" column and what you need to do with the user entered value. 

Please elaborate on the activity you wish to allow.