Set Session variable in javascript function

How can I set session variables with JavaScript ?

Sample Code In Java script:

<script language="javascript" type="text/javascript">

          function SendRequest() {

          var MySessionvalue = '<%= Session["EMP_C"] %>';

          var MyColocn = '<%= Session["COLOCN_C"] %>';

          alert(MySessionvalue);           

          }

< /script>

#How can I set session variables with JavaScript
#Assigning Session variable from Javascript
#How do i set a session variable using javascript?