I am trying to pass a variable that is given it value on onchange

<td align=center><select onchange = "setTandemSwitchString()" name="switchListTable" size="10">
<%= switchListInfo%>

this calls setTandemSwitchString()

function setTandemSwitchString()

strSwitch = document.eoFrame.switchListTable.options[document.eoFrame.switchListTable.options.selectedIndex].value;

document.eoFrame.switchList.value = strSwitch;

I am trying to send strSwitch variable back to the bean so I need it to pass it back as a java variable.

any suggestions?