I created a custom treeview control that inherits from TreeView control. I have my own TreeNodes and event args but when the tree node is rendered I get:
<a id="ctl00_ContentPlaceHolder1_navTreet0" style="text-decoration: none;" onclick="TreeView_SelectNode(ctl00_ContentPlaceHolder1_navTree_Data, this,'ctl00_ContentPlaceHolder1_navTreet0');" href="javascript:__doPostBack('ctl00$ContentPlaceHolder1$navTree','sbda7636b-8ce6-46a7-b92c-35eb4a031ad9')">Home</a>
Notice the s prefixing the id in the __doPostBack args. I could just substring it to get the real id but am curious about why it is even there? It only happens on the root node.