1. 出发和到达
<fielset class="col-sm-6">
<label for="FDestination" >From</label>
<select name="Location" id = "Location" onchange="checkforblank()" >
<option value = "Please Select" >Please Select </option>
<option value="Newport">Newport</option>
<option value="Mahdi">London</option>
<option value="Cardiff">Cardiff</option>
<option value="Cilo">Brazil </option>
</select>
<fielset class="col-sm-6">
<label for="FDestination">To</label>
<select name="LocationTo" id = "LocationTo" onchange="checkforblank()">
<option value = "Please Select">Please Select </option>
<option value="Cardiff">Cardiff</option>
<option value="Mahdi">London</option>
<option value="Newport">Newport</option>
<option value="Cilo">Brazil</option>
</select>
<script>
function checkforblank() {
var location = document.getElementById('Location');
var invalidFrom = location.value == "Please Select";
var locationTo = document.getElementById('LocationTo');
var InvalidTo = locationTo.value == "Please Select";
if (invalidFrom || InvalidTo) {
alert('Please enter first name');
location.className = 'error';
InvalidTo.className = 'error';
}
else {
location.className = '';
}
return !invalid;
}
</script>
.error {
border: solid 5px #FF0
}
当用户选择错误选项 ("Please Choose") 时,我希望所选选项的边框被着色。现在的情况是,当我点击提交后,它会显示警报,然后在一个框中出现颜色,而另一个框则为空,然后它就消失了。
当用户在任一框中选择 "Please Choose" 选项时,我希望在该框中显示错误信息。例如,如果两个框都有 "Please Choose",则两个框都突出显示,或者如果一个框有 "Please Choose" 而另一个框是有效的,则只突出显示一个有错误选项的框。另外,当在警报框中单击“确定”后,这些框将保持突出显示,直到更改为有效选项。