Start Workflow

Installation

Install the farm solution using stsadm or powershell

Add-SPSolution c:\Com.CodePlex.SPC3.StartWorkflow.wsp
stsadm -o addsolution -filename c:\Com.CodePlex.SPC3.StartWorkflow.wsp

Configuration

A good example of a list, is one where users are allowed to create items, but not edit items (eg for a Feedback form on a website)
Say then, you want the users to be able to cancel their feedback via a workflow.

In SharePoint designer, create a new custom button with this as the UrlAction:

{SiteUrl}/_layouts/Com.CodePlex.SPC3/StartWorkflow.aspx?List={ListId}&ItemID={ItemId}&Workflow=Cancel Feedback

If you want the dialog box, use this UrlAction instead:

javascript:SP.UI.ModalDialog.showModalDialog({url:"{SiteUrl}/_layouts/Com.CodePlex.SPC3/StartWorkflow.aspx?List={ListId}&ItemID={SelectedItemId}&Workflow=Cancel Feedback",dialogReturnValueCallback: function(dialogResult, returnValue) { SP.UI.ModalDialog.RefreshPage(SP.UI.DialogResult.OK) }})