how to open outlook's "send mail" from web application (asp.net c# intranet)?

i'm displaying details of employees in a grid view.

i need to go to send mail window of outlook.

<asp:HyperLinkField DataTextField="Email_ID" NavigateUrl="mailto:tonyjo123@gmail.com" />

 will satisfy my reqiurement.

the problem is that i need the selected value from the gridview to be in the "To" field.

 
...