Calculating a sum of a sum

[dinobfc]

i have a transaction form and s ubform within it.
i have a field =quantity*Price this brings the total price for the item and displays it in the subform in the sunform footer i have put in =sum [totalprice]
i then display this on the main form in a different text box but just get an error, is there any way of it display the answer? Please help it is the final part in my system!

 

[dcx693]

i then display this on the main form in a different text box but just get an error

How are you trying to display it? If you're using the controlsource property of the control on the mainform to reference the control with the sum on the subform, try this expression:
Me.subformName.Form.NameOfControl