Not directly, no. Server-side functions live server-side, client-side functions live on the client.
In fact, the only way to get ANY server-side code to run, is to submit the form. ASP.NET unrolls the HTTP headers, unpackages the hidden ViewState variable, re-instantiates objects, and then decides what events to raise based on all of the above.
Then, in your Page_Load handler on the server, use the Request object to check for the presence and/or value of this variable, and call the appropriate server-side method.
ID="cmdUpdateField" runat="server" Text="Update Fields"
//--------------In your code behind page
protected void cmdUpdateField_Click(object sender, EventArgs e)