How to pass onchange actionFunction's new value to oncomplete event JS?

Question

Below is the sample code(I wrote it randomly). oncomplete of the actionfunction, javascript is being called, but the picklist value is being "undefined". I even tried $component.id, but the picklist value is still being "undefined". Any help is much appreciated. Thanks.

<apex:form id="the form">
<apex:pageblocksectionItem>
 <apex:outputlabel> hi </apex:outputlabel>
  <apex:actionregion>
    <apex:inputfield value="{!picklist}" onchange="change();"/>
  </apex:actionregion>
</apex:pageblocksectionItem>

<apex:actionfunction name="change" action={!apexmethod} rerender="theForm" oncomplete"callscript()" />

</apex:form>

<script>
 function script()
{
if(picklist == 'yes')
{
  alert ('random info');
}
}
</script>

Answer 1

To start, you need to reference the field via a selector or id

Lots of stuff to say, but this should solve your immediate issue

<apex:form id="the form">
<apex:pageblocksectionItem>
 <apex:outputlabel> hi </apex:outputlabel>
  <apex:actionregion>
    <apex:input field id="thefield" value="{!picklist}" onchange="change();"/>
  </apex:actionregion>
</apex:pageblocksectionItem>

<apex:actionfunction name="change" action={!apexmethod} rerender="theForm" oncomplete"callscript()" />

</apex:form>

<script>
 function script()
{
if(document.getElementById('{!$Component.thefield}').value == 'yes')
{
  alert ('random info');
}
}
</script>