HIDE & SHOW ON CHANGE DROP DOWN
<html>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js">
</script>
<script>
$(document).ready(function(){
$('#purpose').on('change', function() {
if ( this.value == '1')
//.....................^.......
{
$("#business").show();
}
else
{
$("#business").hide();
}
});
});
</script>
<body>
<select id='purpose'>
<option value="0">Shiva</option>
<option value="1">sandeep</option>
</select>
<br/>
<input type='text' class='text' id='business' name='business' value size='20' style='display:none;'/>
<br/>
</div>
</body>
</html>