Sub Button1_Click
Dim Javascript As String
Javascript="B4A.CallSub('SetTextLabel', true, GetEditText())" 'First parameter, a sub in your app, third parameter, sub you want to call in your php (or whaterver) script
WebViewExtras1.ExecuteJavascript(Javascript)
End Sub
Sub SetTextLabel(data As String)
Label1.Text = data
End Sub