URL Redirecting problem

Hi All,

We have a domain www.emsce.org pointing to the root folder emsce0000, also we have a sub domain beta.emsce.org pointing to a folder inside the root folder(\emsce0000\beta). We have written a script that which is redirecting to the sub domain

if (Request.ServerVariables['SERVER_NAME'] == 'beta.emsce.org')
{
\\redirect to folder beta
}
else if (Request.ServerVariables['SERVER_NAME'] == 'emsce.org')
{
\\redirect to root folder
}

Both of these are working correctly. Now I wanted to have a separate section for administrative puposes for that I am going to use the url http://beta.emsce.org/master and i have created a folder master inside the beta folder and put all the necessary files in that folder. Please note that http://beta.emsce.org/master is not a sub domain . I have added a new section in the redirecting script

else if (Request.ServerVariables['SERVER_NAME'] == 'beta.emsce.org/master')
{
\\redirect to beta\master
}

What is happening now is, when I type http://beta.emsce.org/master on the browser it is showing 'The page cannot be found' and when I type http://beta.emsce.org/beta/master it is redirecting to the correct location. But I wanted the page should come when I use the url http://beta.emsce.org/master
Could you please help me to solve this? It is urgent.