dhtmlxCalendar not rendering properly

Hi,
I am using the dhtmlxCalendr v4.2 and trying to connect the calendar to an input using an icon.

my code is as follows

<script>
myCalendar = new dhtmlXCalendarObject({input: "calendar_input", button: "calendar_icon"});
myCalendar.setPosition(10);
</script>
<body>
<div class="header">
<span><img id="calendar_icon" src="dhtmlx/dhtmlxCalendar/common/calendar.gif" border="0" /></span>
<input id="calendar_input" type="text"  />
</div>

but my calendar that shows up on the creen is not showing correctly and completely. It does not show the dates at all!

aah!
solved! the problem was with my CSS.