function chk_height(){

div1_height=parseInt(document.getElementById("content").style.height) // div1 height
div2_height=parseInt(document.getElementById("div2").style.height) // div2 height
height_offset=div1_height - div2_height // height difference

document.getElementById("content").scrollTop = document.getElementById("div2").scrollTop
document.getElementById("temp_div").style.height = document.getElementById("content").scrollHeight - height_offset

scroll_pos=document.getElementById("content").scrollTop
}