I have the following vb Line that is giving me an error when caption is "".

[VBA]
LblPrice.Caption = Format(CDbl(LblPrice1.Caption) + CDbl(LblPrice2.Caption) + CDbl(LblPrice3.Caption), "$#,##0.00")

[/VBA]

What do I need to do for it to give me the sum even if 1 or more caption's are "" ?