title: Convert string value back to GUID value
body: <p>i have a guid value that i store in my hidden variable. 
  say for eg (303427ca-2a5c-df11-a391-005056b73dd7)</p>
  
  <p>now how do i convert the value from this hidden field back to GUID value (because the method i would be calling expects a GUID value).</p>
  
  <p>thank you.</p>