Regarding the Components in Struts

Hi is thr any way that i can identify the components that are used in JSP being in Struts Action Class.
For example:
My ActionForm will have a property called Staring userName.
And my JSp file will have a component called
<html:text property="userName"/>
and the same can also be like
<html:textarea property="userName"/>

But in porior to the loading of jsp, the action class should identify the component that is used in the JSp..that the component that is used is TextField or TextArea....

Is thr a way for that
If so pls mail me to ganeshkt@nous.soft.net