Plaese help me to understand why this code would generate an empty string?

lParameter newpar1
Set Default To "\\airline-eng\sd\gv doc control\pre_pdf\out"

testpoway = File(AllT(newpar)+".pdf")
MessageBox(newpar) <<< OKAY HERE!!!
Set Default To &defpath

Do Case
Case testpoway = .T. And newpar5 = 2 And newpar6 = 1 &&Signoff DCN and PDF file existed
newpar2.Caption = "The PDF file will be copied to Gainesville!!"
newpar3.Enabled = .T.
newpar7.Value = .T.
Do pushup With AllT(newpar), newpar5, newpar6, 1

lParameter dwgno1

dwgno = "'"+dwgno1+"'"

MessageBox(dwgno) <<< EMPTY STRING!!!