Wbadmin on network share

hi

i have an Windows Server 2008 and

i want to make an backup on network share with wbadmin ...use this syntax :

wbadmin start backup -backupTarget:\\myserver\sharename -include:c:,e: -noVerify

and receive an error messagge that says :

Error. The value of the option backupTarget is missing. See the following syntax.

thanks