Hi ,

 if anyone knows of a way to create a validation rule to ensure that an opportunity must pass through all of the stages before it can reach Closed Won? user should not skip to final stage without completing previous stages.one should pass through all the stages
eg. stages like suspect,proposal , negotiation then closed won. 
He should not jump from suspect to closed won directly he has to move from suspect then proposal later negotiation finally closedwon
I am new to salesforce anyone help me to achieve this with example.
Thanks.