Randomized Evaluation of transorally gastric tube insertion under visual control with the use of video laryngoscope King Vision or under blind

INTERVENTION: The group of gastric tube transorally insertion under visual control with the use of video laryngoscope King Vision. The group of gastric tube transorally insertion under blind. CONDITION: Surgical case under temporary stomach tube insertion PRIMARY OUTCOME: 1.The success rate of gastric tube insertion.; 2.Time required for gastric tube insertion. SECONDARY OUTCOME: 1.The incidence of intratracheal aberration.; 2.The incidence of oral hemorrhage. INCLUSION CRITERIA: Patients undergoing surgery under temporary stomach tube insertion.