function checkDate() { if (!document.getElementById || !document.createTextNode) { return; } var dateField = document.getElementById("date"); if (!dateField) { return; } var errorContainer = dateField.parentNode.getElementsByTagName("span")[0]; if (!errorContainer) { return; } var checkPattern = new RegExp("\\d{2}/\\d{2}/\\d{4}"); var errorMessage = ""; errorContainer.innerHTML = ''; var dateValue = dateField.value; if (dateValue == "") { errorMessage = "Plaese provide a date."; } else if (!checkPattern.test(dateValue)) { errorMessage = "Pleaes provid the date in the defined format"; } if (errorMessage != "") { errorContainer.innerHTML = errorMessage; dateField.focus(); return false; } else { return true; } }
http://dotnet.aspx.cc/file/firstElementChild-lastElementChild-previousElementSibling-nextElementSibling-childElementCount.aspx
<html><head><title>Date example</title>
<style type="text/css">
.error{
color:#c00;
font-weight : bold ;
}
</style>
<script type="text/javascript" src="js/checkDate.js"></script>
</head><body>
<h1>Events Search</h1>
<form onsubmit="return checkDate()">
<p>
<label for="date">Date in the format DD/MM/YY</label>
<input type="text" id="date" name="date" />
<input type="submit" value="Check" />
<br/>(example 26/04/2012) <span class="error"></span>
</p>
</form>
</body></html>
下面是JS代码:// JavaScript Document
function checkDate(){
if(!document.getElementById || !document.createTextNode){
return;
}
var dateField = document.getElementById("date");
if(!dateField){return;}
var errorContainer = dateField.parentNode.getElementsByTagName("span")[0];
if(!errorContainer){return;}
var checkPattern = new RegExp("\\d{2}/\\d{2}/\\d{4}");
var errorMessage = "";
errorContainer.firstElementChild.nodeValue = '';
var dateValue = dateField.value;
if(dateValue == ""){
errorMessage = "Plaese provide a date.";
}else if(!checkPattern.test(dateValue)){
errorMessage = "Pleaes provid the date in the defined format";
}
if(errorMessage != ""){
errorContainer.firstChild.nodeValue = errorMessage;
dateField.focus();
return false;
}else{
return true;
}
}
if (!document.getElementById || !document.createTextNode) {
return;
}
var dateField = document.getElementById("date");
if (!dateField) {
return;
}
var errorContainer = dateField.parentNode.getElementsByTagName("span")[0];
if (!errorContainer) {
return;
}
var checkPattern = new RegExp("\\d{2}/\\d{2}/\\d{4}");
var errorMessage = "";
errorContainer.innerHTML = '';
var dateValue = dateField.value;
if (dateValue == "") {
errorMessage = "Plaese provide a date.";
}
else if (!checkPattern.test(dateValue)) {
errorMessage = "Pleaes provid the date in the defined format";
}
if (errorMessage != "") {
errorContainer.innerHTML = errorMessage;
dateField.focus();
return false;
} else {
return true;
}
}