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<script type="text/javascript">
     var reg = /(^[1-9]([0-9]+)?(\.[0-9]{1,2})?$)|(^(0){1}$)|(^[0-9]\.[0-9]([0-9])?$)/;
     var money = "520.100";
     //000 错
     //0 对
     //0. 错
     //0.0 对
     //050 错
     //00050.12错
     //70.1 对
     //70.11 对
     //70.111错
     //500 正确
     if (reg.test(money)) {
          alert("正确~");
     }else{
          alert("有误~");
     };
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