I'm not well clued up with javascript so I'm having a problem getting the following script to work. I need to check if a name entered is also contained within a message.

<input type="hidden" id="Message" value="<%= rsDetail.Fields("Message") %>">
<input type="hidden" id="FirstName" value="<%= rsDetail.Fields("FirstName")%>">

<script type="text/javascript">
<!--
function NameCheck(){
var FirstName=document.getElementByID('FirstName');
var CardMessage=document.getElementByID('Message');
var aPosition = CardMessage.indexOf('FirstName');

if (aPosition == -1)
alert("Name Not In Message.");
}
-->
</script>

<a href="NextPage.asp" onClick="NameCheck();">Proceed</a>

I'm not well clued up with javascript so I'm having a problem getting the following script to work. I need to check if a name entered is also contained within a message.

<input type="hidden" id="Message" value="<%= rsDetail.Fields("Message") %>">
<input type="hidden" id="FirstName" value="<%= rsDetail.Fields("FirstName")%>">

<script type="text/javascript">
<!--
function NameCheck(){
var FirstName=document.getElementByID('FirstName');
var CardMessage=document.getElementByID('Message');
var aPosition = CardMessage.indexOf('FirstName');

if (aPosition == -1)
alert("Name Not In Message.");
}
-->
</script>

<a href="NextPage.asp" onClick="NameCheck();">Proceed</a>

• javascript

• document.getElementById() returns the element, not the element's value. To get the element's value, you can do document.getElementById('someId').value. – aroth Commented Oct 19, 2011 at 13:14

7 Answers 7

It seems like you are trying to get the value of the input FirstName. getElementById() only returns the node itself. Instead access its value:

var FirstName = document.getElementById('FirstName').value;
var CardMessage = document.getElementById('Message').value;

// Then use the variable `FirstName` instead of the quoted string
var aPosition = CardMessage.indexOf(FirstName);

// Best practice would be to use === for strict type comarison here...
if (aPosition === -1)
  alert("Name Not In Message.");
}

Also, note that you've misspelled getElementById, with a capital D at the end where it should be lowercase.

This what you are trying, I think.

var FirstName=document.getElementById('FirstName').value;
var CardMessage=document.getElementById('Message').value;
var aPosition = CardMessage.indexOf( FirstName );

'FirstName' with quote is string, not the variable FirstName. You need:

// remove the quote, pass the variable FirstName instead of string 'FirstName'
var aPosition = CardMessage.indexOf(FirstName);

EDIT: I missed two things before. First you need to get the value of the node, and second is the uppercase D. So the correct code is:

var FirstName = document.getElementById('FirstName').value;
var aPosition = CardMessage.indexOf(FirstName);

Best way to use jQuery. Your code we can minified to max 2 line:

$("#click").click(function() {
    var found = $('#Message').val().indexOf($("#FirstName").val());
    console.log(found);
});

document.getElementByID should be document.getElementById

The indexOf() method returns the position of the first occurrence of a specified value in a string. This method returns -1 if the value to search for never occurs. Note: The indexOf() method is case sensitive.

Try :

var FirstName=document.getElementByID('FirstName');
var aPosition = CardMessage.indexOf(FirstName);

In your exemple you are looking for the following string FirstName not the value of the variable FirstName