JS半角转全角

<input type="button" onclick="changeAll();" value="半转全" />

changeAll = function(){

//得到FCK编辑器文本内容
var txtstring = FCKeditorAPI.GetInstance("text").EditorDocument.body.innerText; 
var tmp = ""; 
for(var i=0;i<txtstring.length;i++){
if(txtstring.charCodeAt(i)==32){ 
tmp = tmp+ String.fromCharCode(12288); 
}else if(txtstring.charCodeAt(i)<127){ 
tmp = tmp+String.fromCharCode(txtstring.charCodeAt(i)+65248); 
}else{
tmp = tmp+txtstring.charAt(i);
}  
} 
FCKeditorAPI.GetInstance("text").EditorDocument.body.innerText = tmp;
}