<select name="ddl_Minute" id="ddl_Minute" onchange="f()">
<option selected="selected" value="0">0 m</option>
<option value="0.25">15 m</option>
<option value="0.50">30 m</option>
<option value="0.75">45 m</option>
</select><script language=javascript>
//全局变量
var iStart = 0;
function f()
{
var sel = document.all.ddl_Minute;
iNow = Number(sel.options[sel.options.selectedIndex].value);
alert(iNow-iStart);
iStart = iNow;
}
//选择前后2个值之差,
</script>
<option selected="selected" value="0">0 m</option>
<option value="0.25">15 m</option>
<option value="0.50">30 m</option>
<option value="0.75">45 m</option>
</select><script language=javascript>
//全局变量
var iStart = 0;
function f()
{
var sel = document.all.ddl_Minute;
iNow = Number(sel.options[sel.options.selectedIndex].value);
alert(iNow-iStart);
iStart = iNow;
}
//选择前后2个值之差,
</script>
解决方案 »
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