Adding a function to a button

[TGuthrie]

I'm trying to attach a javascript funtion to a button and I am having problems
with it. Original the javascript function is attached to a dynamically created
text string. Well when I want to attach the same function to the button it
won't work, let me know what to do make this button work with the function.

~~~~~Script~~~~~

function addRowClass(tableID, tableBody, instructionArray)
{
// write add link to page
var oTable = document.getElementById(tableID);
if(oTable)
{
// make the link
oAddLink = document.createElement("a");
oAddLink.setAttribute("href", "#");
oAddLink.onclick = function() { addFormRow(tableBody, instructionArray);
return false; }
var oLinkText = document.createTextNode("Add Another Row");
oAddLink.appendChild(oLinkText);

document.body.insertBefore(oAddLink, document.body.firstChild);
}
}

/* main function */ <--The Function I want to attach to button
function addFormRow(tableBody, fieldArray)
{
tableBody = document.getElementById(tableBody);
newRow = document.createElement("tr");
rowNum = tableBody.getElementsByTagName("tr").length - 1; <-- ****The
Error****

for (var i = 0; i <= fieldArray.length; i++)
{
oCell = document.createElement("td");
oInput = document.createElement("input");

switch(fieldArray[0][i])
{
case "text":
createTextbox(fieldArray[2][i], rowNum, fieldArray[1][i], fieldArray[3][i]);

break;

default:
//an input error has occurred. Nothing will be written out to the cell.
break;
}
oCell.appendChild(oInput)
newRow.appendChild(oCell)
}
rowNum += 1;
tableBody.appendChild(newRow)
}

~~~~ERROR~~~~

Line 149 * <-- ****The Error**** Located in the script
"Null" is null

~~~~My Button~~~~
<input type="button" name="Button1" value="Create Row" class="NewRowButton"
value="javascript=addFormRow()">

~~~~End~~~~~

Thanks for the help

[robhuddles]

The function has two arguments - tableBody and fieldArray - that need to get
passed to it when it is called.

Also, your button has two value attributes, which is going to cause problems.
What you want is:
<input type="button" name="Button1" value="Create Row" class="NewRowButton"
onClick="javascript:addFormRow(some_reference_for_ tableBody,
some_reference_for_fieldArray)">

Rob Huddleston
Adobe Dreamweaver Certified Developer