&lt;script type=&quot;text/javascript&quot;&gt;<br /> function checkAll(form) {<br /> if(form.elements[0].checked == true) {<br /> for (i = 1, n = form.elements.length; i &lt; n; i++) {<br /> form.elements[i].checked = true; }<br /> } else {<br /> for (i = 1, n = form.elements.length; i &lt; n; i++) {<br /> form.elements[i].checked = form.elements[i].defaultChecked; } }<br /> }<br /> &lt;/script&gt;<br /> &lt;form name=&quot;checkform&quot; method=&quot;post&quot; action=&quot;&quot; /&gt;<br /> &lt;input type=&quot;checkbox&quot; checked name=&quot;checker&quot; onclick=&quot;checkAll(this.form);&quot; /&gt; 1<br /> &lt;input type=&quot;checkbox&quot; checked name=&quot;2&quot; /&gt; 2<br /> &lt;input type=&quot;checkbox&quot; checked name=&quot;3&quot; /&gt; 3<br /> &lt;input type=&quot;checkbox&quot; checked name=&quot;4&quot; /&gt; 4<br /> &lt;input type=&quot;checkbox&quot; checked name=&quot;5&quot; /&gt; 5<br /> &lt;/form&gt;