javascript - Dropdown form navigation on the same page as another form -

I am looking for a dropdown menu on our website that will appear on all pages of our navigation and navigate This is what I am using on a set of special brand pages:

  & lt; Form & gt; & Lt; Choose name = "url" onchange = "window.location.href = this.form.URL.options [this.form.URL.selectedIndex] .value" style = "font-weight: normal; width: 170px;" & Gt; & Lt; Option value = "" & gt; Choose a brand ... & lt; / Options & gt; & Lt; Option value = "brand-a.html" & gt; A & lt; / Options & gt; & Lt; Option value = "brand-b.html" & gt; B & lt; / Options & gt; & Lt; / Select & gt; & Lt; / Form & gt;   
 This works very well, though there is a conflict between this and other forms (s) that can be displayed on the same page of our site (i.e., shopping cart page , Billing / shipping info). For example, you fill out your billing information, click Submit, and an error comes out from our shopping cart - I'm guessing because the brand form above has no option, and it's submitted before Is trying.  
 Is there any way of both forms on this page?  
 Please tell me if I can provide any additional details to help resolve this issue.  
 Thank you!   
 
 
 Simply select tags can be capitalized. This is valid in HTML5.