title: retrieve value from database when onchange in dropdownbox by jquery
body: <p>This is my html code</p>
  
  <pre><code>&lt;select name="course" id="course" onchange="valuesOfAll(this.value)"&gt;
     &lt;option value=""&gt; select &lt;/option&gt;
     &lt;option value="1"&gt; Diploma in Computing&lt;/option&gt;
  &lt;/select&gt;
  &lt;input name="course_credits" id="course_credits" type="text" /&gt;
  </code></pre>
  
  <p>and my database table is like this</p>
  
  <pre><code>courseId   courseName            courseCredits
    1        Diploma in Computing    5
  </code></pre>
  
  <p>So my request is, if i change the value in the 'select' the 'courseCredits' value should appear in the textbox. for this how can i write jquery code?</p>