This function either logs on a specified user or displays a Log On dialog.

Function Group Execution Windows Embedded Thin Client Mobile Access
LogOn Module Activity Asynchronous Supported Supported Supported Supported


Web Studio Help nction moduleactivity logon.xml d155023e90 LogOn
The name of the user to log on.
The specified user’s password.

optStrUsername and optStrPassword are optional parameters. If they are not specified, then the project will instead display a Log On dialog, to prompt the station’s current operator — whoever it is — to log on.

Returned value

This function returns the following possible values:
Value Description
0 Error (e.g., username or password is invalid) or cancellation.
1 Success.


The following limitations also apply to how the function can be used in project screens in Mobile Access:
  • The function cannot be called from the sub-routine Screen_OnClose in the Screen Script; and
  • You should avoid creating a script that both shows a dialog box (e.g., a message box that is shown using the VBScript function MsgBox or the IWS built-in function ShowMessageBox) and opens or closes a screen. The Mobile Access web interface can display only one screen at a time, and opening a new screen will automatically close the previous one. Depending on the order of execution, this can lead to unexpected behavior such as a dialog box being orphaned or not being shown at all.


Display a Log On dialog:
Log on username Albert with password EMC2:
  LogOn( "Albert", "EMC2" )