Expression issue using query design

[osas]

Please help me solve this issue ; having created table relations in ms Access,I was trying to do a calculation using "Expression" I ran a query and unfortunately I did not get the desired result but the message prompted me a dialog box to "enter parameter value" but then I do not know what to do since I am a beginner. The following is the expression I used,a row by row calculation: " Subtotal: [tblOrdersDetails]![Qty]*[tblBook]![RetailPrice]"

[JoeM]

If you get an enter parameter value, it usually means it does not recognize one of the field names.
So, you most likely did one of the following:
- Mis-typed one of your field names
- Tried to use a field that isn't in your query

If you aren't sure, switch your query to SQL View, and copy and paste the SQL code here so we can review it.

[osas]

Please help me solve this issue ; having created table relations in ms Access,I was trying to do a calculation using "Expression" I ran a query and unfortunately I did not get the desired result but the message prompted me a dialog box to "enter parameter value" but then I do not know what to do since I am a beginner. The following is the expression I used,a row by row calculation: " Subtotal: [tblOrdersDetails]![Qty]*[tblBook]![RetailPrice]"

Thank you JoeM
I have been able to resolve the issue, I used the webaccess expression instead of desktop expression