python search function not working

I need help with part of python code. I have search function which will search for string in file, and retrun it if found, or give Error dialog if not found. Also after Error dialog is closed, give user right to enter correct value. I did't put whole code, but basicly /tmp/ARNE/final1 file looks like:

siu43543, RTWAURT
siu34544, RYAKCCD

and if user enters name for example siu43543, it will reaturn RTWAURT, or give error dialog, and wait for correct value. So my function needs to give error dialog, or the value, if found.

def search(VAR,VAR1):
    global linese
    global linese1
    with open("/tmp/ARNE/final1", 'r') as file:
       for line in file:
              var=re.search(VAR, line)
              if var:
                  linese = line.split(',')[0]
              else:
                  tkMessageBox.showinfo("ERROR", "MISSING ELEMENT") 
                  return Exception 

              var11=re.search(VAR1, line)
              if var1:
                  linese1 = line.split(',')[1] 
              else: 
                  tkMessageBox.showinfo("ERROR", "MISSING PARENT")
                  return Exception      
    return linese
    return linese1 

try:
    search(line1,line1) 
except Exception:
    break