The second argument of the read method is the 'handler' function, i would expect you should provide a function here which will be called with the data.
Note, however, that 'reading the content from a file saved in a webdav directory' is just a normal GET request so you dont need a special dav library. You could for example use the jquery get method:
$.get( "ajax/test.html", function( data ) { $( ".result" ).html( data ); alert( "Load was performed." ); });