unity3d检查消灭数的一个问题

Assets/jiancha.js(15,11): BCE0044: unexpected char: 0xFF08.
function Start () {

}
var sd:int;
var xm:int;
function Update () {
if(gameObject.transform.position.y xm=gameObject.Find("Main Camera").GetComponent(sheji).Xmshu++;
sd=gameObject.Find("Main Camera").GetComponent(sheji).Sdshu;
gameObject.Find("st").GetComponent(GUIText).text="射弹数:" + sd +
" 消灭数:" + xm;
//判断消灭数是否大于20
if（xm > 20){
gameObject.Find("zt").GetComponent(GUIText).text = "恭喜过关";
gameObject.Find("Main Camera").GetComponent(sheji).enabled=false;
}
Destroy(gameObject);
}
}

求大神指点哪错了？

你的条件写对了嘛，是y还是z小于零