How to refer to the value of a textbox in an expression window (Local Report)?

The expression window doesn't need to be the expression window you can open by right-clicking the textbox -> choosing Expression. A textbox has some expression windows which are Font-related expression windows, Alignment-related expression windows, Visibility-related expression window,Border-related expression windows and the Value-related expression window. In the Value-related expression window, I don't need to refer to the value of the current textbox, because it's exactly the value Expression used for the textbox. However I wonder if there is a way to refer to this value in other expression windows of a textbox? Or simply use the exact value expression of the textbox? For example, the value expression of a textbox is `=Fields!ID.Value`, in another expression window (e.g the Color expression window), I want to refer to this value by some keyword if possible like this `=IIF(this.Value > 0, "Green", "Red")`. Currently I have to use the exact expression of the textbox and the expression for its color looks like this `=IIF(Fields!ID.Value > 0, "Green", "Red")`. I hope there is a simple way to refer the value of the current textbox, not through its exact expression, because sometimes the expression is too long to re-type it or even copying-n-pasting the expression is not better than a short keyword. Thanks!