anchor tag repeating controller name asp.net MVC 4

Question

Hi All,
i have following of markup

<a href="controllerName/[email protected][i].Pid">Know more</a>
in one of cshtml.

I redirect user to this page using following javascript
<input type="button" id="btnGoTo" value="ButtonCaption" onclick="window.location.href = '../Product/Index';" />


the problem is when user is redirected to the cshtml page the redirection is happening as;
controllerName/controllerName/ActionMethodName...

Kindly help

thanks in advance