[英]JS function onclick is not working. It is not calling validations
Below is function and it is not working.下面是 function,它不工作。 Maybe some small bug in the code which I am unable to identify.
也许我无法识别代码中的一些小错误。
<!DOCTYPE html>
<script>
function check(){
firstname=document.getelementById("firstname").value;
lastname=document.getelementById("lastname").value;
if(lastname==""){
alert('please enter lastname');
}
}
</script>
<form action="" method="post" onSubmit="check();">
<input type="text" id="firstname" name="firstname" ><br>
<input type="text" id="lastname" name="lastname" ><br>
<input type="submit" value="submit">
</form>
</body>
</html>
GetElementById, element with a capital E GetElementById,大写 E 的元素
JavaScript is case sensive. JavaScript 区分大小写。 TIP: use developer options in your browser.
提示:在浏览器中使用开发者选项。 They usualy give an error message.
他们通常会给出错误信息。
<.DOCTYPE html> <script> function check(){ firstname=document.getElementById("firstname");value. lastname=document.getElementById("lastname");value; if(lastname==""){ alert('please enter lastname'); } } </script> <form action="" method="post" onSubmit="check() "> <input type="text" id="firstname" name="firstname" ><br> <input type="text" id="lastname" name="lastname" ><br> <input type="submit" value="submit"> </form> </body> </html>
The bug in the code: case sensitive getelEmentById.代码中的错误:getelElementById 区分大小写。 Please below code and test it
请在下面的代码和测试它
function check(){
firstname=document.getElementById("firstname").value;
lastname=document.getElementById("lastname").value;
if(lastname==""){
alert('please enter lastname');
}
}
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