Hello i am using pre-chat form using below code

<apex:page showHeader="false">
<!-- This script takes the endpoint URL parameter passed from the deployment page and makes it the action for the form -->
<script type="text/javascript">
(function() { function handlePageLoad() {
var endpointMatcher = new RegExp("[\\?\\&]endpoint=([^&#]*)");
document.getElementById('prechatForm').setAttribute('action',decodeURIComponent(endpointMatcher.exec(document.location.search)[1]));
} if (window.addEventListener) {
window.addEventListener('load', handlePageLoad, false);
} else { window.attachEvent('onload', handlePageLoad, false);
}})();
</script>
<h1>Pre-chat Form</h1>
<form method='post' id='prechatForm'>
Name: <input type='text' name='liveagent.prechat.name' id='prechat_field' /><br />
Email Address: <input type='text' name='liveagent.prechat:Email' /><br />
Department: <select name="liveagent.prechat.buttons">
<option value="573g00000004CBs">Customer Service</option>
<option value="573g00000004CCM">Technical Support</option>
<option value="573a00000000001,573a00000000002">Customer Service if online, otherwise Technical Support</option>
</select><br />
<!-- Creates an auto-query for a matching Contact record’s Email field based on the value of the liveagent.prechat:Email field -->
<input type="hidden" name="liveagent.prechat.query:Email" value="Contact,Contact.Email" />
<input type="hidden" name="liveagent.prechat.save:Email" value="Email__c" />
<input type='submit' value='Request Chat' id='prechat_submit'/>
<style type="text/css">
p {font-weight: bolder }
</style>
</form>
</apex:page>

can you please guide me how can i redirect this pre-chat form to the chat window.

quick response is needed.

Thanks