solved whit a simple
public String getPhoneNumber(String name, Context context) {
String ret = null;
String selection = ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME
+ " like'%" + name + "%'";
String[] projection = new String[] { ContactsContract.CommonDataKinds.Phone.NUMBER };
Cursor c = context.getContentResolver().query(
ContactsContract.CommonDataKinds.Phone.CONTENT_URI, projection,
selection, null, null);
if (c.moveToFirst()) {
ret = c.getString(0);
}
c.close();
if (ret == null)
ret = "Unsaved";
return ret;
}