Question

The object I’m working on is instantiated in JavaScript, but used in VBScript. In one code path, the variable M.DOM.IPt is defined and has a value, in the other however it is not. I need to detect if it has been defined or not. I checked that M.DOM is defined and accessable in both code paths. Every test I have tried simply results in this error:

Error: Object doesn’t support this property or method

I have tried:

• IsEmpty(M.DOM.IPt)
• M.DOM.IPt is Nothing
• isNull(M.DOM.IPt)

Is there any way to detect the variable isn’t defined and avoid the error?

Note: I can put On Error Resume Next in and it will simply ignore the error, but I actually need to detect it and conditionally do something about it.

Answer 1

     Function SupportsMember(object, memberName)       On Error Resume Next        Dim x       Eval('x = object.'+memberName)        If Err = 438 Then          SupportsMember = False       Else          SupportsMember = True       End If        On Error Goto 0 'clears error     End Function