>>Ok that alert will not fire because xx exists and has a value when the assert line is encoutnered, for some reason your code in ocs cannot see that variable and so you are prompted for the parameter. I would start debugging this by putting a suspend just before the statement in the cursoradapter calss and then using the debugger to check the status of xx as a variable.
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>ocs see the variable. when i run one of my reuqery() function variable loose. I would like to see which requery() line firing that prompt. anyway thanks...

Did you try to trap for the error in CursorFill method of your base CA class?