Enbiya - 2015-11-20

hi there, i'm tryig to login my modem user interface. but i have some exceptions. when i get user and password inputtext as an element, i have null. how can i fix it txtUsr,txtPass,btn all of them are null..

WebConversation conversation=new WebConversation();
HttpUnitOptions.setExceptionsThrownOnScriptError( false );
WebResponse webResponse=conversation.getResponse("http://192.168.1.1");


TextBlock txtUsr= (TextBlock) webResponse.getElementWithID("txt_Username");
TextBlock txtPass= (TextBlock) webResponse.getElementWithID("txt_Password");
Button btn= (Button) webResponse.getElementWithID("loginmid");
button.click();