how to convert xml string to datetime and float in sql server 2005?

I refer following article to send datatable in c# to sql server. it works but I want to send datetime and float value to my database. how can I do it as referred article.please help me.

http://ift.tt/1Wf0wX2

cast(colx.query('data(dob) ') as datetime) as dob,
cast(colx.query('data(salery) ') as float)     as salery