create and call parameterized transaction for webdynpro

I have a requirement to call a webdynpro application in a transaction.

i have created a parametrized transaction and it is working fine.

But when i call this parametrized transaction from portal(browser) . The control first go to SAP GUI and the webdynpro application is displaying in SAP GUI.

My question is if a user doesn't have SAP GUI installed in his system , will he able to execute the parametrized transaction from portal.