Javascript Html.Checkbox onchange event

Question

I tried below event in order to reach onchange of checkbox.

 @Html.CheckBox("AutoCalculateMandate", true , new { onchange = "AutoCalculateMandateOnChange" })

Javascript:

function AutoCalculateMandateOnChange() {
    alert("working");
}

When i try above javascript code , alert never displays nothing(not working).

How can i enable/disable below input on Html.Checkbox value changed ?

<input type="text" id="LevyFee" class="form-control" data-required="true" ">

Any help appreciates.

Thanks.

Solution

You can get checkbox as a element in your function by passing this as a reference see updated markup below

<input type="checkbox" value="check" id="AutoCalculateMandate" onchange = "AutoCalculateMandateOnChange(this)"/>
<label for="AutoCalculateMandate">
    Auto Calculate
</label> <br />

Since you're using MVC so it can be achieved like this:

 @Html.CheckBox("AutoCalculateMandate", true , new { onchange = "AutoCalculateMandateOnChange(this)" })

javascript

function AutoCalculateMandateOnChange(element){
     document.getElementById("LevyFee").disabled = element.checked;    
}

Demo