var cur_val = new Array();
var dir = new Array();

function pulse(obj,nr,start,end,stepsize)
{
    if((!cur_val[nr])||(!dir[nr]))
    {
        cur_val[nr] = start;
        dir[nr]=stepsize;
    }
    
    var next = cur_val[nr] + dir[nr];
    var curdir = dir[nr];
    
    if((curdir > 0)&&(next >= end))
        curdir = curdir * -1;
    if((curdir < 0)&&(next <= start))
        curdir = curdir * -1;
        
    obj.style.fontSize = next + "px";
    
    cur_val[nr] = next;
    dir[nr]=curdir;
}