Which Event should be raise to pop up the on screen keyboard when a textbox is clicked in a HTML Webbrowser Control

function PopupKeyboard() {
    try{
        var focusedElement = document.activeElement; // Store the focused element.
        if (focusedElement.readOnly == false) {
            var shell = new ActiveXObject("WScript.Shell");
            var r = shell.Run('"C:/Program Files/Common Files/microsoft shared/ink/tabtip.exe"', 0, true); // This last param is for the execution of the script to stop until the program run in the shell exits. It doesn't work for tabtip.
            setTimeout(function () { // Wait 100 miliseconds before settting the focus again.
                if (focusedElement != null)
                    focusedElement.focus();
            }, 100);
        }
    } catch (Exception) { }
    return false;
}

private static void SetOnClickEvent(ControlCollection controls)
{
	Control childControl = default(Control);
	foreach ( childControl in controls) {
		if (childControl is TextBox) {
			TextBox textbox = (TextBox)childControl;
			textbox.Attributes("onclick") = "PopupKeyboard()";

		} else if (childControl is GridView) {
			GridViewRow row = default(GridViewRow);
			foreach ( row in ((GridView)childControl).Rows) {
				SetOnClickEvent(row.Controls);
			}
		}
		SetOnClickEvent(childControl.Controls);
	}
}

SetOnClickEvent(page.Controls)