Dlookup resulting in null value

[Gavx]

I am trying to run this code but getting a run time error 94 - null value - when it shouldn't be.
I am thinking I have written the Dlookup incorrectly?

Private Sub txtProductName_Click()
Dim iProdType As Integer
Dim ProductID As Integer


iProdType = DLookup("ProductTypeID", "tblProduct", "ProductID" = Forms![frmBooking]![cboProductID].[Value])

Note ProductID in an integer

How can I diagnose this or what could the solution be?

thanks

 

[CJ_London]

the = needs to be in quotes, try

iProdType = DLookup("ProductTypeID", "tblProduct", "ProductID = " & Forms![frmBooking]![cboProductID])

And if this bit of code is in the same form as cboProductID then all you need is

iProdType = DLookup("ProductTypeID", "tblProduct", "ProductID = " & [cboProductID])

Note you do not need the .value - this is the default property

 

[Gavx]

Thanks CJ

I tried

iProdType = DLookup("ProductTypeID", "tblProduct", "ProductID = " & Forms![frmBooking]![cboProductID])

because this code runs in a subform to frmBooking which is where cboProductID is located.

I am now receiving the error 3075 Syntax error (missing operator) in query expression 'ProductID = '.

 

[CJ_London]

sounds like your control cboProductID is null (or perhaps named something else)

 

[Gavx]

If I put a breakpoint on that statement and run the code and hover the cursor over the " & Forms![frmBooking]![cboProductID]) part the following displays under teh cursor;

Forms![frmBooking]![cboProductID]="482" which is what I expect. But when I hover the cursor over iProdType the value of 0 is reported.

 

[CJ_London]

iProdType will be 0 until the dlookup line of code has been executed - hit F8 to move to the next line then hover over iProdType

And just to confirm, there is a ProductID in tblProduct numbered 482 and a field called ProductTypeID?