Xml Validation Problem!.

how do i validate xml schema without resorting to programming
i gat xerces jar files in ma classpath, but so far the parser only
validates xml- defined with DTD's when i switch to xml schema i get an error
??
   or isnt there no way for apache's xerces parser to directly validate xml schema's
, like i does for xml with dtd's. fill me in roooooom.