Using <f:selectitems> in html to make dependent drop down list using javascript -

i able select value 1 drop down , depending on value, able disable drop down list. want when 2nd drop down disabled should show '(select one)'.

this code:

<h:selectonemenu id="tier" isrequired="true"                                 value="#{allocationtemplatedetailsbackingbean.allocationrule.allocationfulfillparameters.fulfillmenttierstr}">                                 <f:selectitems id="tierlist"                                     value="#{allocationtemplatedetailsbackingbean.fulfillmenttierlist}" /> .... ... </h:selectonemenu>  , javascript function follows:  function controlfulfillmenttierdropdownlist()          {             var strategy = document.getelementbyid('dataform:strategy');             if(strategy != null)             {                 if(strategy.value == 5)                 {                      var fulfillmenttierdropdownlist = document.getelementbyid('dataform:tier');                     fulfillmenttierdropdownlist.disabled = true;                      var supplytypepanel = document.getelementbyid('supplytypediv');                     supplytypepanel.style.display = "none";                 }             }         } 

from tierlist, first value in list '(select one)', whenever strategy.value==5, want disable tierlist dropdown (which have done disable attribute of tier), want set value visible '(select one)' instead of older value present.