Steps to Reproduce:
1. Input the following script, watch the map info:
    ldtp.click('frmTasks', 'btnNew')
2. Then input a script:
    ldtp.click('frmTasks', 'btnNewNon')


Actual Results:
1. Map all of components inside the frmTasks.
2. Remap all of components inside the frmTasks again.

Expected Results:
2. It should check the map of 'btnNewNon' button whether it exists in current window but for all of components, 
then add the map of control to map-file after it found.


Other:
In fact, We always just need to check whether the specific component is available aftet maped all of controls under the window.