如何创建子域名以在我的网站上发布3-4 .aspx页面

I am new in asp.net 2.0 My question: I created one asp.net website and hosted it by getting domain and one of my client ask me to post his 3-4 asp.net pages as a sub domain of my main domain, so can anybody expain what to do and if there is any coding please expain me in detail. I am new in asp.net 2.0 My question: I created