now = new Date(),hour = now.getHours()                        
if (hour<06) {document.write("各位网友，凌晨好！")}                        
else if (hour<08) {document.write("各位网友，早上好！")}                        
else if (hour<12) {document.write("各位网友，上午好！")}                        
else if (hour<14) {document.write("各位网友，中午好！")}                        
else if (hour<17) {document.write("各位网友，下午好！")}                        
else if (hour<22) {document.write("各位网友，晚上好！")}                        
else {document.write("各位网友，夜里好！")}