input只允许输入正整数

onkeyup= "if(this.value.length==1){this.value=this.value.replace(/[^1-9]/g,'')}else{this.value=this.value.replace(/\D/g,'')}"

                   onafterpaste= "if(this.value.length==1){this.value=this.value.replace(/[^1-9]/g,'0')}else{this.value=this.value.replace(/\D/g,'')}"