function zmien_form(form,name){
 	length_form=form.action.length;
	length_good_form = length_form-8;
 		if (form.action.substring(length_good_form)=="?opcja=0" ||form.action.substring(length_good_form)=="?opcja=1" ||form.action.substring(length_good_form)=="?opcja=2" ){
			form.action = form.action.substring(0,length_good_form)
		}
        	form.action = form.action+"?opcja="+name;
		
        return true;
    }