Dropdown using javascript onchange

Question

I have a simple drop down and I want to have it so that if the user selects Have a Baby the message changes to Have a Baby, but for any other selection. The message stays the same (nothing), but this isn't working. Can someone please help. Please play with my jsfiddle.

http://jsfiddle.net/Z9YJR/ Here is the html

<select id="leave">
  <option value="5">Get Married</option>
  <option onchange="changeMessage()" value="100">Have a Baby</option>
  <option value="90">Adopt a Child</option>
  <option value="15">Retire</option>
  <option value="15">Military Leave</option>
  <option value="15">Medical Leave</option>
</select>

<div id="message"></div>

Here is the js

function changeMessage() {
    document.getElementById("message").innerHTML = "Having a Baby!!";
}

It looks like you have to relocate the function for jsfiddle specifically. I believe this is their way of encapsulating any code you write so that it doesn't interfere with any of their code. http://jsfiddle.net/Z9YJR/5/ — Shmiddty, Aug 22 '12 at 19:36

Claudio Redi · Accepted Answer · 2015-06-30T11:59:33.790

Something like this should do the trick

<select id="leave" onchange="leaveChange()">
  <option value="5">Get Married</option>
  <option value="100">Have a Baby</option>
  <option value="90">Adopt a Child</option>
  <option value="15">Retire</option>
  <option value="15">Military Leave</option>
  <option value="15">Medical Leave</option>
</select>

<div id="message"></div>

Javascript

function leaveChange() {
    if (document.getElementById("leave").value != "100"){
        document.getElementById("message").innerHTML = "Common message";
    }     
    else{
        document.getElementById("message").innerHTML = "Having a Baby!!";
    }        
}

jsFiddle Demo

A shorter version and more general could be

HTML

<select id="leave" onchange="leaveChange(this)">
  <option value="5">Get Married</option>
  <option value="100">Have a Baby</option>
  <option value="90">Adopt a Child</option>
  <option value="15">Retire</option>
  <option value="15">Military Leave</option>
  <option value="15">Medical Leave</option>
</select>

Javascript

function leaveChange(control) {
    var msg = control.value == "100" ? "Having a Baby!!" : "Common message";
    document.getElementById("message").innerHTML = msg;
}

You can pass the select object into the function for greater abstraction... onchange="leaveChange(this)"... function leaveChange(elem){ if(e.value... — FrankieTheKneeMan, Aug 22 '12 at 19:43

score 4 · Answer 2 · answered Aug 22 '12 at 19:40

It does not work because your script in JSFiddle is running inside it's own scope (see the "OnLoad" drop down on the left?).

One way around this is to bind your event handler in javascript (where it should be):

document.getElementById('optionID').onchange = function () {
    document.getElementById("message").innerHTML = "Having a Baby!!";
};

Another way is to modify your code for the fiddle environment and explicitly declare your function as global so it can be found by your inline event handler:

window.changeMessage() {
    document.getElementById("message").innerHTML = "Having a Baby!!";
};

score 3 · Answer 3 · answered May 15 '13 at 12:50

easy

<script>
jQuery.noConflict()(document).ready(function() {
    $('#hide').css('display','none');
    $('#plano').change(function(){

        if(document.getElementById('plano').value == 1){
            $('#hide').show('slow');    

        }else 
            if(document.getElementById('plano').value == 0){

             $('#hide').hide('slow'); 
        }else
            if(document.getElementById('plano').value == 0){
             $('#hide').css('display','none');  

            }

    });
    $('#plano').change();
});
</script>

this example shows and hides the div if selected in combobox some specific value

Because obviously everyone who has a javascript problem uses or wants to use jQuery! — Jeroen van den Broek, May 23 '15 at 20:00

Dropdown using javascript onchange

3 Answers3

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