selectedIndex
HTML
<select>
<option value="">Select</option>
<option value="10000">Minimum Coverage</option>
<option value="25000">Average Coverage</option>
<option value="">Other</option>
</select>
JavaScript
document.getElementsByTagName('select')[0].onchange = function() {
var index = this.selectedIndex;
var inputText = this.children[index].innerHTML.trim();
alert(inputText);
}