c# - Button Click in Gridview to Update SQL value -

i have gridview pulling values customername, acctnum, phonenum, city, address , lastleak. data pulls great pull lastleak thats 5 years or older. have button on right once driver check hits button , row updates lastleak today's date. reason can't work know has close can shine light.

here gridview:

<asp:gridview id="gridview1" runat="server" autogeneratecolumns="false" datasourceid="lastleakcheck" width="950px" onrowcommand="gridview1_rowcommand">     <columns>         <asp:boundfield datafield="customername" headertext="customername" sortexpression="customername" />         <asp:boundfield datafield="acctnum" headertext="acctnum" sortexpression="acctnum" />         <asp:boundfield datafield="phonenum" headertext="phonenum" sortexpression="phonenum" />         <asp:boundfield datafield="city" headertext="city" sortexpression="city" />         <asp:boundfield datafield="address" headertext="address" sortexpression="address" />         <asp:boundfield datafield="lastleak" headertext="lastleak" sortexpression="lastleak" />         <asp:buttonfield buttontype="button" commandname="updatedate" headertext="update date" showheader="true" text="completed"   />        </columns> </asp:gridview> <asp:sqldatasource id="lastleakcheck" runat="server" connectionstring="data source=server;initial catalog=propane;user id=id;password=pass;integrated security=true"      selectcommand="select customername, acctnum, phonenum, city, address, lastleak custinfowhere lastleak &lt;= convert(datetime, '4-6-2012' )order convert(datetime, lastleak) asc" ></asp:sqldatasource> 

and click event row:

protected void gridview1_rowcommand(object sender, gridviewcommandeventargs e) {

    if (e.commandname == "updatedate")     {          int index = convert.toint32(e.commandargument);         gridviewrow row = gridview1.rows[index];          cn = new sqlconnection(@"data source=server;initial catalog=propane;user id=id;password=pass;integrated security=true");         cmd = new sqlcommand("update custinfo set lastleak='4/7/2017' customername='@customername'", cn);          cmd.parameters.addwithvalue("@customername", row.cells[0].text);          cn.open();         cmd.executenonquery();         cn.close();         gridview1.databind();     }  }