Use the following jQuery snippet to get the value of the selected option in the select box.

First create a new jQuery function

function getSelectedOption(id){
     $('#' + id).val();
}

Then create your select box.

<select id="selectBox">
<option>Select</option>
<option>Red</option>
<option>Blue</option>
<option>Green</option>
<option>Yellow</option>
<option>Purple</option>
</select>

Now all you have to do to get the selected value for the select box is call the function you just created.

var text = getSelectedOption('selectBox');