Question: how to change dropdown selected value using jquery?
Answer: To display the selected drop down box value. $('#country').val();
To set a drop down box value to 'China'. ... 
To set a drop down box value to 'United State'. ... 
To set a drop down box value to 'Malaysia'. ... 
To disable the 'United State' option in drop down box. ... 
To enable the 'United State' option in drop down box.