Disable a button from form view in Openerp-7

I have created a button on OpenERP_7. Its basic use is to print the selected record in the tree view. Its like the More button used in OpenERP-7. The problem here I m facing is that I dont want this button to be shown on the form view.Right now its being displayed on tree view as well as form view but I want it to be view only on tree view.Since its not a simple button thats why Im having problems. Do I have to make changes in the web module or can this be done with any user access permissions? I really need guidance on this. Plz guide me to achieve this.