rolloverImageRegexp = /(_f[0-9])?((\.jpg)|(\.png)|(\.gif))/ ;
$( document ).ready ( function () {
    $( 'a img.wk_button_blue' ).each ( function () {
        $( this ).hover (
            function () { this.src = this.src.replace ( rolloverImageRegexp , '_f2$2' ) ; } ,
            function () { this.src = this.src.replace ( rolloverImageRegexp , '$2' ) ; }
        );
    } );
} ) ;

function hoverImageStart ( img ) {
    if ( img )
        img.src = img.src.replace ( rolloverImageRegexp , '_f2$2' ) ;
}

function hoverImageEnd ( img ) {
    if ( img && $( img ).hasClass ( 'active' ) == false )
        img.src = img.src.replace ( rolloverImageRegexp , '$2' ) ;
}