Assigning Java varible value to Javascript varible

How to assign a java variable vale to an javascript varible. I have tried the following scripting elements:

<%
double x=23.35;
%>
var temp='<%= x %>';
var temp="<%= x %>";
var temp='${x}';
they returned an output as follows:

<%= x %>
<%= x %>
${x}

if the above scripting tags are used without quotes then they are not accepted.
Actually I am not working on an web application, but calling this jsp file from a java code. I am working on SWT browser for uploading google maps.