[gnukfu]

If the issue is a non-compete agreement/contract generally you have to show that there is a likelihood of irreparable harm/injury if the preliminary injunction is not granted.

If the case makes it to trial the judge reviews the agreement using a test typically developed under the case law of that state (common law). There are a number of factors that are considered. Geographic scope, length of time, norms within the industry, and public policy are some factors that are considered. It varies from state to state depending on how the case law developed within that state.