JQM and OpenStreetMap


I have developed mobile application using Jquery mobile, Phonegap for IOS and Android and I would like add OpenStreenMap to my application. I tried code from http://wiki.openstreetmap.org/wiki/OpenLayers_Simple_Example in my application, and I changed only this rows

map = new OpenLayers.Map("divMap");// my change name of div element
var mapnik         = new OpenLayers.Layer.OSM();
var fromProjection = new OpenLayers.Projection("EPSG:4326");   
var toProjection   = new OpenLayers.Projection("EPSG:900913"); 
var position       = new OpenLayers.LonLat(latitude,longitude).transform( fromProjection, toProjection);// my       change, latitude and longitude are valid values  of my geolocation 
var zoom           = 15;

map.setCenter(position, zoom ); 

This code is in a function, that runs after user clicks on button.
Result - I see “button” on left top side (+,-) and on right-down side I see “Data CC-By-SA by OpenStreetMaps”
This result I see twice bellow.
If I click on button +, in error console I see thsi error -

TypeError: ‘null’ is not an object (evaluating ‘this.size.w’)

If I run this code in desktop browser, result is the same. This is extract from Firebug

Data CC-By-SA by OpenStreetMap

Please, can anybody help me?