icefaces outputProgress problem

[sa sam]

i am using inputfile tag to upload file,
my problem is the process of outputProgress bar not showing step by step (e.g. 10%, 20%...,100%)

it shows directly 100%, even though the size of file is big.

in large file, display of outputProgress shows blank (i.e. 0%) & suddenly get 100%.

i want to show that process step by step.

my code is as follows -

                             <ice:inputFile id="inputFileName" 
					actionListener="#{FileController.uploadFile}"
					progressListener="#{FileController.fileUploadProgress}"/>
					
				<ice:outputProgress value="#{FileController.fileProgress}"/>