Conditional Statements in Arc Map 10 (field Calculator)

I’m attempting to calculate the values of a field based on IF THEN statements in ArcMap 10 (in field calculator) but I haven’t succeeded yet on that.

What I want to add is the following expression:

IF [FIELDNAME1] = [FIELDNAME2] then

[FIELDNMCH] = "no change" else

[FIELDNMCH] = "change"

END IF

The values in the fieldnames are texts.

Any help on that?