記号を全角やら半角に変換するやつ〜〜〜ぅ

JavaScript 
String.prototype.toAscii = function(){
　return this.replace(/”/g,'"').replace(/’/g,"'").replace(/([！-〜 ])/g,
　　function (char){ return String.fromCharCode(char.charCodeAt(0) - 65248)} );
};

String.prototype.toZenkaku = function(){
　return this.replace(/"/g,'”').replace(/'/g,"’").replace(/([!-~])/g,
　　function (char){ return String.fromCharCode(char.charCodeAt(0) + 65248)} );
};