js厘米与英寸尺码转换

 <style type="text/css">
     #txt_cm1, #txt_inch1, #txt_inch2, #txt_cm2 {
         width: 63px;
         height: 26px;
         margin: 0 5px;
         border: solid 1px #ccc;
     }
     #txt_inch1, #txt_cm2 {
         background: #e7e7e7;
         text-align: right;
         padding-right: 5px;
         width: 58px;
     }
     .converterCalculation{
         overflow: hidden;
         border: 1px solid #e7e7e7;
         padding: 15px;
     }
     .converterCalculation .calculation{
         color: #000;
         height: 33px;
         font-weight: bold;
         width: 365px;
         padding-right: 0;
     }
     .converterCalculation div.calculation input.last {
         height: 26px;
         line-height: 26px;
         color: #fff;
         background: #999;
         padding: 0 5px;
         margin-left: 5px;
     }
 </style>
 <div class="converterCalculation">
   <div class="calculation">Converter:
     <input type="text" id="txt_cm1" onkeypress="keyPress(this)" onkeyup="keyUp(this)" onblur="onBlur(this)" />cm&nbsp;&nbsp;
     <input type="text" id="txt_inch1" disabled="disabled" value="0.00" />inch
     <input type="button" class="last" value="Calculation" onclick="Calculation(1)" />
   </div>
   <div class="calculation">Converter:
     <input type="text" id="txt_inch2" onkeypress="keyPress(this)" onkeyup="keyUp(this)" onblur="onBlur(this)" />inch
     <input type="text" id="txt_cm2" disabled="disabled" value="0.00" />cm&nbsp;&nbsp;
     <input type="button" class="last" value="Calculation" onclick="Calculation(2)" />
   </div>
 </div>
 <script type="text/javascript">

 function keyPress(that){
     that.value.match(/^[\+\-]?\d*?\.?\d*?$/)?that.t_value=that.value:that.value=that.t_value;
     that.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/)&&(that.o_value=that.value)
 }
 function keyUp(that){
     that.value.match(/^[\+\-]?\d*?\.?\d*?$/)?that.t_value = that.value:that.value = that.t_value;
     that.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/) && (that.o_value=that.value)
 }
 function onBlur(that){
     that.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?|\.\d*?)?$/)?(
             that.value.match(/^\.\d+$/)&&
             (that.value=0+that.value),that.value.match(/^\.$/)&&
             (that.value=0),that.o_value=that.value
         ):that.value = that.o_value
 }
 function Calculation(type){
     var cm1,inch1,inch2,cm2;
         type==1 && (
                 cm1=eval($("#txt_cm1").val()),
                 cm1==undefined&&(cm1=0),inch1=(cm1/2.54).toFixed(2),
                 $("#txt_inch1").val(inch1)
             );
         type==2 && (
                 inch2=eval($("#txt_inch2").val()),
                 inch2==undefined&&(inch2=0),cm2=(inch2*2.54).toFixed(2),
                 $("#txt_cm2").val(cm2)
             )
 }
 </script>