10. A method of preventing cross-site scripting, the method comprising: parsing an HTML e-mail message to create a document object model (DOM) tree wherein the DOM tree includes a plurality of branches, the plurality of branches including at least one branch having only known elements; utilizing a model hook of an e-mail program to derive a normal element filter; applying the normal element filter to the DOM tree, the filter executing as a plug-in in a browser in a computing device; creating a modified DOM tree wherein the at least one branch having only known elements is excluded from the DOM tree and wherein the excluding of the at least one branch from the DOM tree is performed such that remaining branches of the DOM tree are still connected with one another; and applying a script analyzer filter to the modified DOM tree to create a final DOM tree having only unknown element types.
10. A method of preventing cross-site scripting, the method comprising: parsing an HTML e-mail message to create a document object model (DOM) tree wherein the DOM tree includes a plurality of branches, the plurality of branches including at least one branch having only known elements; utilizing a model hook of an e-mail program to derive a normal element filter; applying the normal element filter to the DOM tree, the filter executing as a plug-in in a browser in a computing device; creating a modified DOM tree wherein the at least one branch having only known elements is excluded from the DOM tree and wherein the excluding of the at least one branch from the DOM tree is performed such that remaining branches of the DOM tree are still connected with one another; and applying a script analyzer filter to the modified DOM tree to create a final DOM tree having only unknown element types. 24. A method as recited in claim 10 wherein the DOM tree includes a root node and a plurality of nodes that are organized into a plurality of levels that form a tree-like structure, each of the plurality of nodes representing an element in the HTML e-mail message and being a parent or a child to another node, the plurality of levels including a first level, the first level including only the root node, each of the levels in the DOM tree other than the first level consisting only of children of the nodes of another level, the method further comprising: applying the normal element filter to the DOM tree using the model hook of the e-mail program, the model hook indicating expected characteristics of the DOM tree, the expected characteristics including at least one selected from the group consisting of: 1) a maximum number of levels in the DOM tree; and 2) a maximum number of Javascripts the email can have; and excluding one or more selected elements from the DOM tree based on whether the selected elements are in accordance with the expected characteristics of the DOM tree.