DECLARE SYNTAX

[harpalshergill]

I am trying to convert a declare syntax from SQL to MySQL
the syntax is as follows:
declare @x int;
set @x = (SELECT max(ixBugEvent) FROM bugevent);

UPDATE bugevent
SET ixAttachment = (SELECT max(ixAttachment) FROM attachment),
ixBug = (SELECT max(ixBug) FROM bug)
WHERE ixBugEvent = @x;

but it is giving me an error. can anyone help.
thanks for your time in advance...