Too many open brackets error [Solved]

Hello guys !
I'm having this problem with this expression !

( yy( "Camera" ) + ( ( Y( "Player" ) + 300 ) - yy( "Camera" ) ) * 0.05 ) + ( Cos(Random(628)) * AMPLITUDE( "Camera" ) )

The expression editor don't let me enter this (even I entered it before !)

is there any way to make it work with all this brackets ???

[SOLUTION] I HAD TWO VARIABLES WITH THE SAME NAME , I FOUND THIS OLD POST
http://community.clickteam.com/threads/89949-Put-an-alterable-string-in-a-string-problem