Userform text box to a cell but with the result value of IF statement

Hi
I am trying to create a production userform, there are many fields to add and some have calculations.

I would like to add the values, but with and IF Statement that if the sum is greater than a 100 multiply it by .000453592

.Cells(lRow, 5).Value = Val(Me.trai7.Text) + Val(Me.trai8.Text) + Val(Me.trai9.Text)

I am new creating userforms and I have no idea how to to IF statements in this kind of situation

thanks