Scrolling HTML Basics, Part I: Positioning A Scroll Box - Doc JavaScript | WebReference

Scrolling HTML Basics, Part I: Positioning A Scroll Box - Doc JavaScript


Positioning A Scroll Box

There are many ways to position a scroll box. You can position it in absolute coordinates, but the desired location may change because of an ad put at the top of the page, for example. In this column we use the table method. We place a dummy GIF at the top left and the bottom right corners of the table. We fill the table with some example headlines that will span the desired height of the scroll box. Here is the table in our page:

<TABLE ALIGN=RIGHT WIDTH=275>
<TR>
<TD ALIGN=LEFT><IMG NAME="pht" SRC="t.gif" ALT="" WIDTH=1 HEIGHT=1></TD>
</TR>
<TD>
<img class="bullet" src="bullet.gif">
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<p>
</TD>
</TR>
<TR><TD ALIGN=RIGHT><IMG NAME="phb" SRC="t.gif" ALT="" WIDTH=1
HEIGHT=1></TD></TR>
</TABLE>

We then compute the coordinates of these GIFs in our scrolling box code:

bnrLft=document.images.pht.x;
bnrTop=document.images.pht.y;
bnrRit=document.images.phb.x;
bnrBot=document.images.phb.y;
bnrWid=bnrRit-bnrLft;
bnrHit=bnrBot-bnrTop;

and we use these coordinates to call the scroll box API:

scrollBox(bnrLft, bnrTop, bnrWid, bnrHit,'jscolumns3.html',50)

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Produced by Yehuda Shiran and Tomer Shiran

Created: November 23, 1998
Revised: November 23, 1998

URL: http://www.webreference.com/js/column30/position