jQuery(document).ready(function(){
lastBlock = jQuery("#a1");
maxWidth = 180;
minWidth = 40;

jQuery("ul.numbers li a").hover(
function(){
jQuery(lastBlock).animate({width: minWidth+"px"}, { queue:false, duration:400 });
jQuery(this).animate({width: maxWidth+"px"}, { queue:false, duration:400});
lastBlock = this;
}
);
});