how to get multiple selected values and items from listbox using javascript?

It’s as follows :

 

var src = document.getElementById('leftSelect');
var selected = [];
var options = src.options.length;
for (var i=0; i < options ; i++)
{
     if(src.options[i].selected)
     {
          alert(src.options[i].text);
          alert(src.options[i].value);
     }
}

 

<html>
<select id="leftSelect" onclick="" name="edu_quli" size="10" multiple="multiple">
<option value="10th">10th</option>
<option value="+2">+2</option>
<option value="Any Graduation">Any Graduation</option>
<option value="Any Post Graduation">Any Post Graduation</option>
<option value="Arts Post-Graduation">Arts Post-Graduation</option><option value="Science Post-Graduation">Science Post-Graduation</option>
<option value="Commerce Post-Graduation">Commerce Post-Graduation</option>
<option value="Technical/Professional Post-Graduation">Technical/Professional Post-Graduation</option>
<option value="Management Post-Graduation">Management Post-Graduation</option>
<option value="Other Post-Graduation">Other Post-Graduation</option>
<option value="Diploma">Diploma</option>
<option value="Others">Others</option>
</select>
</html>