>I have subclassed the cBizObjMaintForm. Placed a bizobj on the form with a prarameterized view. If I run the form like that I get no errors so I think the bizobj is OK...
>
>As per the Doc, in the bizobj postinithook() I have added the code to addviewparameter ie...
>this.addviewparameter('vp_bfname','thisform.pageframe.page.textbox')

Did you cut and paste this code here? If so, the second parameter is probably wrong (it doesn't look like a correct object reference)

This.AddViewParameter("vp_bfname", "ThisForm.PageFrame.Page1.TextBox.Value")

>(I'm still not exactly sure what should be in the second parameter), but,
>If I run the form with this code I still works OK.

The second parameter tells MM's where to get the value of the parameter before a Requery() is performed.

>
>In the prerequeryhook I set the value of all view parameters to '%' (for testing porposes)
>

If the view parameter(s) are defined by form fields, and you've added them via AddViewParameter(), this shouldn't be necessary.

>I have place a ctextboxcontaimer on the selection criteria page and set the cviewparamter property to vp_bfname (matching the view parameter in the local view)
>

Which class library is that control in? It doesn't sound familiar. At any rate, are you attempting to check to see if the value the user entered is unique? If not, leave this property empty.