function vert_scroller(viewportId,innerholderId,aspeed){
    var viewportDiv=document.getElementById(viewportId);
    
    viewportDiv.style.overflow='hidden';
    var innerDiv=document.getElementById(innerholderId);
    innerDiv.style.padding=viewportDiv.offsetHeight + 'px' + ' 0';
    var innerDivHeight=innerDiv.offsetHeight;
     
    var speed = (aspeed!=null)?aspeed:1;
    
    var currpos=0;
     
    this.scrollDown=function(){
        this.slide(1 * aspeed);   
    }
   
    this.stopScroll=function(){
        if (viewportDiv.slideint){window.clearInterval(viewportDiv.slideint);viewportDiv.slideint=null;}
    }

    this.slide=function(step){
            
            if (viewportDiv.slideint){window.clearInterval(viewportDiv.slideint);viewportDiv.slideint=null;}           
            viewportDiv.slideint=window.setInterval(
                    function(){   
                        //document.getElementById("debug").innerHTML=viewportDiv.scrollHeight;                                                    
                        currpos+=step;                                           
                        if (currpos>=innerDivHeight-(viewportDiv.offsetHeight)) {                      
                            currpos=0;
                        }                       
                        viewportDiv.scrollTop = currpos;  
                    }            
                    ,70
            );
     }       
 }