tabs are overlapping in custom masthead par

Hi,

We have customized the masthead par file and added few tabs in the par file.  The problem here is when the window is in maximize mode, tabs are displaying properly but when the window is minimized / reduced the size, the tabs are overlapping.   I checked all the <td> <tr> tags and everything is closed perfectly.  Tried to change few options in CSS too but no luck.  Can anyone advise how to resolve this.

Thanks,

Vijaya.