Question

This is my try at creating a registration page however after the for loop whatever follows does not execute and I’m at a loss as to why?
Below is the javascript code and the form

<script type='text/javascript'>
myArray = ['username','email','password','password2'];
reply = ['User Name','Email','Password','Password Again'];
message = "Please Type you're ";
start = "<font color = red size='-1'>";
end = "</font>";
test = 10;
obj = validate();
alert (obj);
function validate(){

for (var i=0; i<=myArray.length; i++) {
               if (document.getElementById("in"+myArray[i]).value == "")
               {
                   document.getElementById(myArray[i]).innerHTML = start+message+reply[i]+end;
                   test = 30;
               }
                }
alert ("test");
}

<form action="echo.php" method="post" name="register" onsubmit="return validate();">
<table>
    <tr>
      <td width="185"><font size="2">First Name</font></td>
      <td width="499">
        <input id = "infirst_name" name="first_name" type="text" /><div id="first_name"></div></td>
    </tr>
    <tr>
      <td><font size="2">Last Name</font></td>
      <td><input id = "inlast_name" name="last_name" type="text" /><div id="last_name"></font></div></td>
    </tr>
    <tr>
      <td><font size="2">Username*</font></td>
      <td>
        <input id = "inusername" name="username" type="text" /><div id="username"></div></td>
    </tr>
    <tr>
      <td><font size="2">Email*</font></td>
      <td><input id = "inemail" name="email" type="text" /><div id="email"></div></td>
    </tr>
    <tr>
      <td><font size="2">Password*</font></td>
      <td><input id = "inpassword" name="password" type="password" /><div id="password"></div></td>
    </tr>
    <tr>
      <td><font size="2">Repeat Password*</font></td>
      <td>
        <input id = "inpassword2" name="password2" type="password" /><div id="password2"></div></td>
    </tr>
    <tr>
    <tr>
      <td><font size="2">I have read and Agree to the Terms and Conditions</font></td>
      <td>
        <input id = "incheckme" name="checkme" type="checkbox" /><div id="checkme"></div></td>
    </tr>
    <tr>
      <td><input type="submit" value="Register" /></td>
      <td>&nbsp;</td>
    </tr>
  </table>
</form>

Answer 1

Try fixing your loop:

for (var i=0; i < myArray.length; i++) {

JavaScript will stop executing anything if it encounters an uncaught error. In your case it seems that you’ve looped past the last element (and tried to set innerHTML on an undefined object).