Alert when a particular value from dropdown is selected

Question

I have a Dropdown(select) in a website that is not controlled by me.But it can be modified by javascript,html,jquery..etc(they have provided web applet for doing so)

This dropdown can be identified an ID 'Zdd_1'. All i want if the user selects "Yes" in the dropdown then only then an alert should come. W hen the user navigates to the page. the dropdown might be Yes or some other value, but i dont care then.

I need this alert only when the state of the drop down changes from any value to "YES". I am not much into jquery and ajax, so if this can be done done simply( mean just using javascript)it would be great.

Answer 1

It can be easly done with the help of jQuery.

$('#Zdd_1').change(function(){
    if($(this).val() === 'yes')
        alert("Hi, I'm alert!");
});

where Zdd_1 be the id for the select element.

If you want, of course you can use only javascript.

Javascript:

    function selectChange(element) {
        if (element.options[element.selectedIndex].value == 'Yes')
            alert("Hi, I'm alert!");
    }

Html:

<select id="Zdd_1" onchange="selectChange(this)">
    <option value="Maybe">Maybe</option>
    <option value="Yes">Yes</option>
    <option value="No">No</option>
</select>

Answer 2

Try this

    var dropdown = document.getElementById("Zdd_1");
    dropdown.onchange = function(event){
       if(dropdown.value=="Yes"){
         alert("Your message")
       }
    }

or check here working demo

Answer 3

On change of dropdown , you can check whether the changed value is "Yes" or not, if it is Yes then alert the text you want .

Try this

Html

<select onchange="changeddl(this)">
    <option value="Maybe">Maybe</option>
    <option value="Yes">Yes</option>
    <option value="No">No</option>
</select>

javascript

function changeddl($this)
{
    if($this.value=="Yes")
    {
        alert("Whatever you want to alert!");
    }
}

You can check the fiddle here

Answer 4

Try something like this:

Demo

You can also call a function on onchange event.