Specified cast is not valid.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.InvalidCastException: Specified cast is not valid.
Source Error:
Line 179: private void btnClear_Click(object sender, System.EventArgs e)
Line 180: {
Line 181: foreach (TextBox t in this.Controls)
Line 182: {
Line 183: Response.Write(t.ID.ToString());