js对字符串进行加密和解密

function compileStr(code){ //对字符串进行加密       
  var c=String.fromCharCode(code.charCodeAt(0)+code.length);
 for(var i=1;i<code.length;i++)
  {      
   c+=String.fromCharCode(code.charCodeAt(i)+code.charCodeAt(i-1));
 }   
 return escape(c);   }




//字符串进行解密 
function uncompileStr(code){      
 code=unescape(code);      
 var c=String.fromCharCode(code.charCodeAt(0)-code.length);      
 for(var i=1;i<code.length;i++)
 {      
  c+=String.fromCharCode(code.charCodeAt(i)-c.charCodeAt(i-1));      
 }      
 return c;   }