getting error calculting the total of gridview cells using javascript

How many rows and columns you  have in the grid ?

Do one thing....

var gridview1 = document.getElementById('<%=grdview1.ClientID %>');
gridview1.rows[gridview.rows.length -1].cells[0].innerHTML=total;


Please try this...

hi using this code also:getting same error
gridview.rows[gridview.rows.length -1].cells[0].innerHTML=total;
Microsoft JScript runtime error: Object expected

Don't use "gridview.rows.length - 8". To go to the last of the grid, use "gridview.rows.length - 1".

Cells[7] means 8th column correct but it is grid you're having only one cell correct.

Try the below one.
gridview.rows[gridview.rows.length -1].cells[0].innerHTML=total;

First you need to understand how the clientid will be created.

var gridViewCtlId = '<%=gv.ClientID%>';
var grid = document.getElementById(gridViewCtlId);
var gridLength = grid.rows.length;
var sum = 100; //store the actual value here.

grid.rows[gridLength - 1].cells[0].innerHTML = sum;

I have tested and this is works for me.

try this....
Your control name total correct but u have mentioned as "lblTotal" and check stirng concatenation also.

var lbl = document.getElementById('<%=Gridview1.ClientID%>') & 'total';
lbl.text = total.toString();

The line is wrong :

document.getElementById("total").innerHTML = total.toString(); //display

You can't directly access the control which is inside the gridview (any databound controls).

You have take the client ID for the Total text box and use it or else you can iterate the gridview.rows ( var gridview = document.getElementById('<%=Gridview1.ClientID %>').getElementsByTagName("input");) and you can find the textbox in it.

Hope this helps you.