Display a div on pageload

Question

I am passing div name in the query string from one html page and retrieving that div name on the other html page. Now I want to display that specific div on the page.My code is

function onLoad()
{    
    var divname=window.location.search.substring(1);    
    document.getElementById(divname).style.display="block";    //error is in this line
}

But I am getting an error as "object expected". please help me

Please do put code inside a code-block so it's much easier to read and for us to help. edit: thanks. — jdepypere, Jan 26 '13 at 17:19
What's the value of the `divname` variable? Do you have corresponding element with such id? — Darin Dimitrov, Jan 26 '13 at 17:20
divname is variable which holds value of the div name which I want to display — user1838922, Jan 26 '13 at 17:24
Log the count of elements that match your divname to make sure it is finding it correctly. `console.log(document.getElementByID(divname0).length);` . Your error is indicating that it cannot apply the style.display to a null object. — Ben Felda, Jan 26 '13 at 17:29

score 3 · Answer 1 · edited May 23 '17 at 12:03

The window.location.search property returns the part of the URL that follows the ? symbol, including the ? symbol.

So for example it might return ?paramname=paramvalue. When you call substring(1) on it you get paramname=paramvalue which is what gets passed to the document.getElementById function which obviously is wrong because such element does doesn't exist on your DOM.

You could use the following javascript function to read query string parameter values:

function onLoad() {    
    var divname = getParameterByName('divname');    
    document.getElementById(divname).style.display = 'block';
}

This assumes that you have a query string parameter name called divname:

?divname=some_div_name

Adjust the parameter passed to the getParameterByName function if your query string parameter is called differently.

You might also want to introduce error checking into your code to make it more robust:

function onLoad() {    
    var divname = getParameterByName('divname');    
    var divElement = document.getElementById(divname);
    if (divElement != null) {
        divElement.style.display = 'block';
    } else {
        alert('Unable to find an element with name = ' + divname);
    }
}

I have copied this code as it is but I am getting an error on line no 2 in "onLoad()" function, it says "object expected" — user1838922, Jan 26 '13 at 18:15
Did you declare the `getParameterByName` function? I have linked to it in my answer: http://stackoverflow.com/questions/901115/how-can-i-get-query-string-values/901144#901144 Make sure that this function is declared before using it. — Darin Dimitrov, Jan 26 '13 at 18:17

score 0 · Answer 2 · answered Jan 26 '13 at 17:54

What I am suggesting is place your js at the end of the html code (before </body> tag). Do not use a function.

<html>
    ...
    ...
    ...
    <body>
    ...
    ...
    ...
        <script>
            var divname=window.location.search.substring(1);    
            document.getElementById(divname).style.display="block"; 
        </script>
    </body>
</html>

score 0 · Accepted Answer · edited Jan 27 '13 at 14:09

0

I have re-written my function and it is working, code is like this

function load()  
{  
    var divname = window.location.search.substring(1);  
    var params=divname.split('=');  
    var i=1;  
    alert(params[i].substring(0));  
    document.getElementById(params[i].substring(0)).style.display='block';  
}

edited Jan 27 '13 at 14:09

New Developer

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answered Jan 26 '13 at 18:26

user1838922

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Display a div on pageload

3 Answers3