onclick Javascript Problem

Giganews Newsgroups
Subject: onclick Javascript Problem
Posted by:  mailing_list_99…@yahoo.com (Jim Bond)
Date: 3 Sep 2003


I have found myself in the position of having to manage & "hack" a web
site built by someone else.  I am trying to make a modification to the
javascript code and have been unable to get this working. I admit that
I am a total javascript beginner, but have read google & purchased the
o'reilley javascript book.  So far, all I've been able to achieve are
numerous javascript errors!

Currently, we have a drop-down box which triggers an "onchange" event.
I would like to reproduce some of this functionality with a simple
button or text link & therefore need to use the "onclick" event.

Current javascript for "onchange" looks like this:

function setExtent(obj){

var sExt=obj.value;


var x1,y1,x2,y2;
var s;

//get coordinates from string
var i = sExt.indexOf(",");

if(i>0) {
x1 = parseFloat(sExt.slice(0,i));
sExt = sExt.slice(i+1);

i = sExt.indexOf(",");

if(i>0) {
y1 = parseFloat(sExt.slice(0,i));
sExt = sExt.slice(i+1);

i = sExt.indexOf(",");

if(i>0) {
x2 = parseFloat(sExt.slice(0,i));
sExt = sExt.slice(i+1);

y2 = parseFloat(sExt);

// alert(x1+","+y1+","+x2+","+y2);

//get map
var map = top.mapwindow.document.mapApplet.getMap();

//get FloatRectangle object
var ext = map.getExtent();

//set Extent boound

//change map extent
map.setExtent(ext, null);

//force repaint


The HTML for the drop down box looks like this:

<select name="theme" size=1 onChange="setExtent(this)">
<option value="10350350,3380230,10582000,3531280">Location</option>

So basically what happens is when someone selects that option from the
drop down list, they are taken to the coordinates on the map (per the

How can this be duplicated using a text link or button with

Thanks a bunch for your help!