Restrict entering anything but numbers in a form field with javascript

javascript:

<SCRIPT TYPE="text/javascript">
<!--
// copyright 1999 Idocs, Inc. http://www.idocs.com
// Distribute this script freely but keep this notice in place
function numbersonly(myfield, e, dec)
{
var key;
var keychar;

if (window.event)
   key = window.event.keyCode;
else if (e)
   key = e.which;
else
   return true;
keychar = String.fromCharCode(key);

// control keys
if ((key==null) || (key==0) || (key==8) || 
    (key==9) || (key==13) || (key==27) )
   return true;

// numbers
else if ((("0123456789").indexOf(keychar) > -1))
   return true;

// decimal point jump
else if (dec && (keychar == "."))
   {
   myfield.form.elements[dec].focus();
   return false;
   }
else
   return false;
}

//-->
</SCRIPT>

html

<FORM ACTION="../cgi-bin/mycgi.pl" METHOD=POST>
U.S. ZIP Code: 
  <INPUT NAME="dollar" SIZE=5 MAXLENGTH=5
   onKeyPress="return numbersonly(this, event)">
  <INPUT TYPE=SUBMIT VALUE="go">
</FORM>

Problem - calling a function in <script> tags from dynamic ajax results does not get executed by the browser

Resolution - make a pixel image and call the function with the onload event in the image

<img src="some_image.jpg" onload="someFunction();">

Include this javascript to make PNG 24 bit transparencies work properly in IE 5.5 and 6

<!--[if lt IE 7]>
<script language="JavaScript">
function correctPNG() // correctly handle PNG transparency in Win IE 5.5 & 6.
{
   var arVersion = navigator.appVersion.split("MSIE")
   var version = parseFloat(arVersion[1])
   if ((version >= 5.5) && (document.body.filters)) 
   {
      for(var i=0; i<document.images.length; i++)
      {
         var img = document.images[i]
         var imgName = img.src.toUpperCase()
         if (imgName.substring(imgName.length-3, imgName.length) == "PNG")
         {
            var imgID = (img.id) ? "id='" + img.id + "' " : ""
            var imgClass = (img.className) ? "class='" + img.className + "' " : ""
            var imgTitle = (img.title) ? "title='" + img.title + "' " : "title='" + img.alt + "' "
            var imgStyle = "display:inline-block;" + img.style.cssText 
            if (img.align == "left") imgStyle = "float:left;" + imgStyle
            if (img.align == "right") imgStyle = "float:right;" + imgStyle
            if (img.parentElement.href) imgStyle = "cursor:hand;" + imgStyle
            var strNewHTML = "<span " + imgID + imgClass + imgTitle
            + " style=\"" + "width:" + img.width + "px; height:" + img.height + "px;" + imgStyle + ";"
            + "filter:progid:DXImageTransform.Microsoft.AlphaImageLoader"
            + "(src=\'" + img.src + "\', sizingMethod='scale');\"></span>" 
            img.outerHTML = strNewHTML
            i = i-1
         }
      }
   }    
}
window.attachEvent("onload", correctPNG);
</script>
<![endif]-->

Disable a checkbox via HTML or javascript.

<INPUT TYPE="checkbox" NAME="MyCheckbox" VALUE="Select Me" DISABLED>

document.forms[0].MyCheckbox.disabled = true;

This bit of javascript will check and uncheck all checkboxes in a group of checkboxes. The checkboxes are grouped by naming all the checkboxes by the same name.

Javascript Code:

function checkUncheckAll(checkAllState, cbGroup)
{
        // Check that the group has more than one element
        if(cbGroup.length > 0)
        {
                // Loop through the array
                for (i = 0; i < cbGroup.length; i++)
                {
                        cbGroup[i].checked = checkAllState.checked;
                }
        }
        else
        {
                // Single element so not an array
                cbGroup.checked = checkAllState.checked;
        }
}

HTML Code:

<input type=checkbox name=checkall onclick="checkUncheckAll(this, grp1);">
<input type=checkbox name=grp1 id=bx1>
<input type=checkbox name=grp1 id=bx2>
<input type=checkbox name=grp1 id=bx3>
<input type=checkbox name=grp1 id=bx4>

When you need to diable selection of text in a page use the following events in the wrapping tag. This is useful if you use javascript ondblclick and don't want the text to be selected.

onmousedown will stop the selection in Firefox. IE will still select text though so you must also use onselectstart to keep IE from selecting the text.

<td onmousedown="return false;" onselectstart="return false;">