Lookup table

<i><b>Originally posted by : Neil (neilthorn10@hotmail.com)</b></i><br />I have produced a lookup table which will load a set of fields into a drop down menu.<br /><br />If the user does not select a field from the lookup table then the value of the system is severely compromised. I have added an if statement on the asp page were the data is to be stored on the database - If ((Request.Form("unit")="")) Then<br /> Response.Write "<A HREF='javascript:history.go(-1)'>"<br /> Response.Write "please enter a value<A/>"<br />End If<br />However I receive an error message - Microsoft JET Database Engine error '80004005' <br />You cannot add or change a record because a related record is required in table 'dropdown'. /webpub/sufs/feedback_ac.asp, line 50 <br /><br />I receive the message because no field has been selected prior to the user submitting the form.<br /><br />What am I doing wrong?<br />Cheers<br />Neil<br />