How to change company from X++

The changeCompany statement is used to alter the database settings to another (separate) company. The syntax of the statement is:
changeCompany ( Expression ) Statement
Here is the code

static void main()
{
CustTable custTable;
;
// Assume that you are running in company ‘aaa’.
changeCompany(‘bbb’) // Default company is now ‘bbb’.
{
custTable = null;
while select custTable
{
// custTable is now selected in company ‘bbb’.
}
}
// Default company is again set back to ‘aaa’.

changeCompany(‘ccc’) // Default company is now ‘ccc’.
{
// Clear custTable to let the select work
// on the new default company.
custTable = null;

while select custTable
{
// custTable is now selected in company ‘ccc’.
}
}
// Default company is again ‘aaa’.
}