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When a select box requires on the fly validation, HTML and JavaScript doesn’t quite support any way of reverting to a previous choice if the validation fails. You cant trigger an onchange event without first updating the select box to a different value. On the other hand, onclick occurs before the choice is made.
If you set a “selected” tag within an option tag on page load, you can easily revert to a previous value by resetting the form or running reset() on the form. However this kinda makes the selected value pretty static.
Follow up:
The following example will firstly show the javascript code
Code:
<script type="text/javascript"> | |
| |
var selectList_cache; // Variable for remember previous choice | |
| |
function validateList(val) | |
{ | |
if(isValid()) | |
{ | |
alert("Validated successfully!"); | |
} | |
else | |
{ | |
alert("Failed the validation so reverting"); | |
document.getElementById("selectList").value=selectList_cache; | |
} | |
} | |
</script> |
Followed by the HTML select box,
Code:
<select name="selectList" id="selectList" onclick="selectList_cache=this.value" onchange="validateList(this.value);return false"> | |
<option value="1">1</option> | |
<option value="2">2</option> | |
<option value="3">3</option> | |
<option value="4">4</option> | |
</select> |
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Brinley Ang is a sysadmin, web dev, coder, geek boy, jedi knight fragger, caffine addict, deaf meloncholic and rockstar wannabe. Listens to the sex pistols and a wide assortment of heavy metal.
Thanks!!!