function rollover(){
    var preLoad = new Object();
    $('img.rollover,input.rollover').not("[src*='_o.'],[src*='_d.']").each(function(){
        this.imgOrig = this.src;
        this.imgType = this.imgOrig.substring(this.imgOrig.lastIndexOf('.'));
        this.imgName = this.imgOrig.substr(0, this.imgOrig.lastIndexOf('.'));
        this.imgOver = this.imgName + '_o' + this.imgType;
        preLoad[this.src] = new Image();
        preLoad[this.src].src = this.imgOver;
        $(this).hover(
            function (){
                this.src = this.imgOver;
            },
            function (){
                this.src = this.imgOrig;
            }
        );
    });
    $('.rollsibling').each(function(){
        var target = $(this).siblings('img.rollover').not("[src*='_o.'],[src*='_d.']");
        $(this).hover(
            function (){
                target.each(function(){
                    this.src = this.imgOver;
                })
            },
            function (){
                target.each(function(){
                    this.src = this.imgOrig;
                })
            }
        );
    });
}
$(document).ready(rollover);