私のコードは次のとおりです。
<!doctype html>
<html lang="en">
<head>
<title>Testing the textarea</title>
<style type="text/css"></style>
<script type="text/javascript" src="validation.js"></script>
</head>
<body>
<div id="wrapper">
<span id="error_box" style="display:none;"></span>
<form name="storyTeller" method="get" action="#" onSubmit="return validateForm()">
<p class="title">
<label for="title">TITLE:</label>
<input type="text" id="title" name="title" required onBlur="validateTitle(title)"/>
</p>
<textarea name="entry" id="entry" rows="10" cols="45" onBlur="validateEntry(entry)">
</textarea>
<input type="submit" value="submit" />
</form>
</div>
</body>
</html>
validation.js の内容:
function validateTitle(title){/*validating the title*/
if (isNaN(document.getElementById('title').value)){
document.getElementById('title').style.background="#ccffcc";
document.getElementById('error_box').style.display="none";
return true;
}
else{
document.getElementById('error_box').innerHTML='Please enter a valid title';
document.getElementById('error_box').style.display="block";
document.getElementById('title').style.background="red";
return false;
}
}
function validateEntry(entry){/*validating the entry*/
var x=document.getElementById('entry').value;
x = x.trim();
if((x=="")||(x==null)){
document.getElementById('entry').style.background="red";
document.getElementById('error_box').innerHTML = 'Where is your story';
document.getElementById('error_box').style.display="block";
return false;
}
else{
document.getElementById('entry').style.background="#ccffcc";
document.getElementById('error_box').innerHTML='';
document.getELementById('error_box').style.display="none";
return true;
}
}
function validateForm(){/*validating the form*/
var error = 0;
if(!validateTitle('title')){
document.getElementById('error_box').style.display="block";
error++;
}
if(!validateEntry('entry')){
document.getElementById('error_box').style.display="block";
error++;
}
if(error > 0){
return false;
}
}