fix some shift start and other button Errors!

employeemanagement/src/components/layout/ManageShift.js

@@ -46,25 +46,25 @@ class ManageShift extends Component {
     render() {
         const worklist = this.props.todayList && this.props.todayList.length ? (
             this.props.todayList && this.props.todayList.map(w => {
-                const startWork = w.startShift !== '' ? (
+                const startWork = w.startShift !== "" ? (
                     <button disabled type="button" className="btn btn-success btn-sm btn-special">Start Work</button>
                 ) : (
                     <button onClick={this.handleCreatEvent} id="startShift" type="button" className="btn btn-success btn-sm btn-special">Start Work</button>
                 )
 
-                const startBreak = w.startBreak === '' && w.startShift === '' ? (
+                const startBreak = w.startBreak !== '' && w.startShift !== '' ? (
                     <button disabled type="button" className="btn btn-success btn-sm btn-special">Start Lunch Break</button>
                 ) : (
                     <button onClick={this.handleUpdateEvent} id="startBreak" type="button" className="btn btn-success btn-sm btn-special">Start Lunch Break</button>
                 )
 
-                const endBreak = w.endBreak === '' && w.startBreak === '' ? (
+                const endBreak = w.endBreak !== '' && w.startBreak !== '' ? (
                     <button disabled type="button" className="btn btn-success btn-sm btn-special">Lunch Break Finish</button>
                 ) : (
                     <button onClick={this.handleUpdateEvent} id="endBreak" type="button" className="btn btn-success btn-sm btn-special">Lunch Break Finish</button>
                 )
 
-                const endWork = w.endShift === '' && w.endBreak === '' ? (
+                const endWork = w.endShift !== '' && w.endBreak !== '' ? (
                     <button disabled type="button" className="btn btn-success btn-sm btn-special">Close Work</button>
                 ) : (
                     <button onClick={this.handleUpdateEvent} id="endShift" type="button" className="btn btn-success btn-sm btn-special">Close Work</button>