Stuff

in class:	public Course_Catalog__c formCi {get; set;}

in constructor:	public Course_Catalog__c formCi {get; set;}

in vf page:

    <apex:pageBlock title="Course Instance - Bulk Update" mode="detail" id="filters">
        <apex:pageBlockSection title="Course Instance Filters" columns="4" showHeader="true" id="ciFiltersHeader">
	        <apex:form style="margin:15px 0;">
	            <apex:inputField value="{!formCi.Location__c}" />
	            <apex:inputField value="{!formCi.Course_Type__c}" />
	            <apex:inputField value="{!formCi.Start_Date__c}" />
	            <apex:inputField value="{!formCi.End_Date__c}" />
	            <apex:commandButton value="Filter" action="{!filterCiList}" id="filterCiListButton"/>
	        </apex:form>
        </apex:pageBlockSection>
    </apex:pageBlock>