function increase_decrease_font(a)
{
    
        var size=parseInt(document.getElementById("news_text").style.fontSize);
        if(!size || a==3)
        size=11;
        if(a==1 && size<19)
        size+=1;
        else
        {
        if (a==2 && size>9)
        size-=1;
        }
        var size2=size-1;
        document.getElementById("news_text").style.fontSize=size+"px";
        var all_tds=document.getElementsByTagName("td");
        for (var t=0; t<all_tds.length; t++)
        all_tds[t].style.fontSize=size2+"px";
}