One problem, two possible problems:
The guaranteed problem: The comma before WHERE is bogus. You only use a comma between multiple set name=value pairs, never after the last one.
sql_update1 = " Update UYELER SET BAKIYE ='1', WHERE id = '" & var3 & "';"
(1) If your BAKIYE field data type is INT then you should *NOT* put apostrophes around the 1.
(2) If your ID field data type is INT then you should *NOT* put apostrophes around the var3 value.
Actually, you should only use apostrophes around either of those values if the fields in question are some kind of text field: TEXT, VARCHAR, MEMO, etc. If they are any kind of number (INT or LONG or DOUBLE) then kill the apostrophes.
USUALLY, ID fields are numbers. And since you are assigning the value 1 to BAKIYE, I would guess that it *probably* is a number, too. So *probably* you don't need or want any apostrophes in that query.
Finally, you don't have to put a semicolon on the end of the query. You can, but it is 100% optional.
So my *GUESS* is that all you need is this:
But, again, it depends entirely on what the data types are of those fields.
sql_update1 = "Update UYELER SET BAKIYE =1 WHERE id = " & var3