Animate passing variable

Animate passing variable

I am creating a sliding image gallery and am trying to use this line:

$('#images_wrapper').animate({left:"-197px"},1500);

This would move the entire div of images to the left but only works once. I was trying to put the current position-197 in there:

var position = $('#images_wrapper').css("left");
position = position.replace('px','');

This would remove "px" and return 197. How do I place this variable in the upper jQuery statement? I've tried everything I can imagine.

Thanks!