in the below code , the alert box is appearing in another window when values are not entered in the fields. but i want the alert box to appear in the same window of html page( detail.htm).how can i do this?
detail.htm:
<body>
<h1> Product: </h1>
<form action="product.php" method="post" >
<input type="text" name= "product_id" size="15" />
<input type="text" name= "price" size="10"/>
<input type = "submit" value = "enter" />
</form>
</body>
product.php:
if (empty($_POST["product_id"]) || empty($_POST["price"])) {
echo "<script>alert('You must enter both values.')</script>";
} else {
include 'product.htm';
}
Copyright Notice：Content Author:「kalvin」，Reproduced under the CC 4.0 BY-SA copyright license with a link to the original source and this disclaimer.
Link to original article：https://stackoverflow.com/questions/7443492/showing-alert-box-in-php