var currentImage = 1;
var totalImage;

function  changeCurrentImage( numberImage ) {
    var oldId = $( ".slideActiveBtn" ).attr("id").split("_")[1];
    
    if ( oldId != numberImage ) {
        $("#n"+numberImage).fadeIn();// removeClass( "hideImage" );
        $("#na_"+oldId).addClass( "slideNoActiveBtn" );
        $("#na_"+oldId).removeClass( "slideActiveBtn" );

        $("#n"+oldId).fadeOut();//addClass( "hideImage" );;
        $("#na_"+numberImage).removeClass( "slideNoActiveBtn" );
        $("#na_"+numberImage).addClass( "slideActiveBtn" );

    }

    return false;s
}

function changeImage(){
    if ( currentImage >= totalImage ) {
        currentImage = 0;
    }
    currentImage++;

    changeCurrentImage( currentImage );
}

$(document).ready(function(){
    var slideImage = $( ".slideImage" );
    totalImage = slideImage.length;

    setInterval( changeImage, 8000 );
});