Hi,
Have a hidden field in your jsp.
Every time you select an item from the combo ,set the hidden field value to the selected item...
This can be done in a javascript function , for ex.
in a javascript function
selectCombo()
document.formName.hiddenField.value= document.formName.comboBox.value;
now call the
servlet from here
document.formName.action=ServletCombo;
document.formName.submit();
Give the function selectCombo() in the onChange() attrirbute of the combo box.
From the servlet you can access the hidden fields value
Using this as the parameter you can execute ur sql command , get the record set , populate a vector or an ArrayList and return to your JSP with the values so as to populate the next combo with these values....
Hope I have not complicated things...
Cheers!
Menon