multicheck combobox with lost focus when select item :/

I try to use this example http://www.codeproject.com/KB/combobox/CheckComboBox.aspx to create multicheck combobox. Everything is all right, but when user select item in dropdown list it close and need anoth开发者_C百科er time click on it and select next item.

It is possible that when I fires onClick and dropdown show i t don't hide unless mouse lost focus on combobox ?

In the comments on the page you linked to, someone posted previously (August 2007) this exact question - and someone else responded with this alternative implementation as the solution: http://www.codeproject.com/KB/combobox/checkedcombobox.aspx