Usage examples of js Form.elements[i]_form effects

Copy code The code is as follows:

//Check whether the form element is empty
function check(Form )
{
for (i=0;iif(Form.elements[i].value == "")
{
// The first letter e of the Form attribute elements should be lowercase
alert(Form.elements[i].name "Cannot be empty!");
Form.elements[i].focus();
// The specified form element gets focus
return;
}
}
Form.submit();
}
Call

Message person:
Message subject:
Message content:
< input name="Button" type="button" class="btn_grey" value="Submit"
onClick="check(form1)">