ColdFusion – get file name before cffile upload
<cffunction name="getClientFileName" returntype="string" output="false" hint="">
<cfargument name="fieldName" required="true" type="string" hint="Name of the Form field" />
<cfset var tmpPartsArray = Form.getPartsArray() />
<cfif IsDefined("tmpPartsArray")>
<cfloop array="#tmpPartsArray#" index="local.tmpPart">
<cfif local.tmpPart.isFile() AND local.tmpPart.getName() EQ arguments.fieldName>
<cfreturn local.tmpPart.getFileName() />
</cfif>
</cfloop>
</cfif>
<cfreturn "" />
</cffunction>
source: http://www.stillnetstudios.com/get-filename-before-calling-cffile/