The ComboBox is useless in all cases except the simplest web pages.
Using the combo box control has a significant problem when attempting to include the combo box in a panel that is absolutely positioned on a web page, or contained within a modal dialog panel to be displayed on the web page.
In both cases, the drop down information is not located directly under the combo box.
When the combo box is used on a web page in a relative position, the drop down information is located in the correct position: directly under the combo box, left aligned with the combo box.
When I position the panel at 0, 0, then the drop down list is displayed under the combo box in the correct position: immediately below and left aligned.
Using the combo box control has a significant problem when attempting to include the combo box in a panel that is absolutely positioned on a web page, or contained within a modal dialog panel to be displayed on the web page.
In both cases, the drop down information is not located directly under the combo box.
When the combo box is used on a web page in a relative position, the drop down information is located in the correct position: directly under the combo box, left aligned with the combo box.
When I position the panel at 0, 0, then the drop down list is displayed under the combo box in the correct position: immediately below and left aligned.