Improper use of boolean expressions

[sifuentes]

I am trying to do a tag that will concatenate two parameters in a label. One parameter is text with the name of the component, and the other parameter is a yes/no parameter for existing equipment. I added a third parameter Existing Text that I want to leave blank for new equipment, and display (E) foe existing. The tag would concatenate Name + Existing Text

I created three parameters:

Name (text)
Existing (yes/no)
Existing Text (text)

I am trying to make Existing Text work with this formula:

if (Existing = 1, "(E)", "")

But I keep receiving a message saying "Improper use of boolean expressions"

Can someone help with this please, or tell if this is possible?

Thanks,

[Alex Page]

Yes/no results are implied....as below should work

If (Existing,"(E)","")

[twiceroadsfool]

Regardless of the format being wrong, it wont let you do that with a text parameter. Concatenate isnt possible in Revit. And Formulas arent possible with Text parameters.

[Alfredo Medina]

Regardless of the format being wrong, it wont let you do that with a text parameter.

Alex's solution is correct, though, since in this case "Existing" is a Yes/No parameter.

Concatenate isnt possible in Revit. And Formulas arent possible with Text parameters.

True. Text parameters cannot be used in formulas. The only text possible in formulas is the text value that one wants to assign to a text parameter, as the <result-if-true>, <result-if-false> parts of an IF formula.

[sifuentes]

Thanks to everyone, everything's working now.

What I meant by concatenate is using several parameters in the same label.