Changing sales stage
It's not "unoptimized". it's just bad.


your JS code shouldn't contain CSS manipulation (unless you are actually making complex animations) 
even when your if and for statements have a single line following it, that code should be wrapped in { .. }
use === when comparing values, unless you explicitly require behaviour, that is provided by == loose comparison
you should use meaningful variable names, instead of el1, el2, etc.
none of this required jQuery
don't define variables in the middle of a function