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>