View Full Version : zooming in script on button press

03-15-2012, 12:12 AM

I've been working on creating a script that zooms the entire webpage. Other than using "CTRL" + "+" keys (generally compatible with all browsers) to zoom in inside a web browser, I want to put it in a different format, as a button; it would be even easier to use.

The problem is that I can't figure out how to make it work/ why it does not work. The following is my code:

<script type = "text/javascript">

document.onkeydown = function(zoomin) {
var key;
zoomin = zoomin || event;
key = zoomin.keyCode;
key == 43;
return false;

if (key == 17) {
return true;
return false;

<h1>Is this appearing to get bigger?</h1>
<button onclick="javascript: function('zoomin');">Zoom in</button>



Basically I was trying to use a DEC code as the code for the "CTRL" and "+" keys; then put them into a function. The "return true" under the IF statement means that I want it to hold so that the "+" key can be read as part of the script, and therefore make the page zoom in. Once that happens, it returns false.

I would appreciate any help/ suggestions. I will also try to look for a way to reset the page (100%) or zoom out as well.

03-15-2012, 01:47 AM
This cannot possibly be your code, can it?

1. A comparison with no depending command like if/while etc?

key == 43;

2. An anonymous function inside another function that will never be called?

return false;

3. The semicolon on the first line of this code is not wrong, but highly unusual ...
4. Also in the button onclick you are only defining an anonymous function without calling anything

Bottom line: You need to learn more about functions, function references and functions calls