Dropdown onchange function into html

Question

I want to use Dropdown onchange function into html to pass value, it works fine in submit button, But I want to use Dropdown onchange, Pls help how to do it?

<form method="post" action=" ">
    <div align="center">
        <select name="value">
            <option value="">Show Value</option><br />
            <option value="2"> 2  </option><br />
            <option value="5"> 5  </option><br />
            <option value="10"> 10 </option><br />
            <option value="20"> 20 </option><br />
        </select>
        <input type="submit" name="submit" value="Submit">
    </div>
</form>

Answer 1

you should add the onChange to the <select> element like this

<form method="post" action=" ">
    <div align="center">
        <select name="value" onChange="this.form.submit()">
            <option value="">Show Value</option><br />
            <option value="2"> 2  </option><br />
            <option value="5"> 5  </option><br />
            <option value="10"> 10 </option><br />
            <option value="20"> 20 </option><br />
        </select>
        <input type="submit" name="submit" value="Submit">
    </div>
</form>