dot net namespace error in XSLT 2.0

I get below error on calling dot net code within my XSLT file

error: The type or namespace name 'com' could not be found in the global namespace (are you missing an assembly reference?)

This is code snippet-

<msxsl:script language="C#" implements-prefix="callCode">
<msxsl:using namesp开发者_C百科ace="global::com.myassembly.crs.app.services.contentTypes"/>

<![CDATA[

public int GetValue()

{

Test1 t = new Test1();

return t.GetValue();

}

]]>
</msxsl:script>

---

You need to specify an assembly reference.

Use the <msxsl:assembly> extension element for that.