Passing string parameter in JavaScript function

Change your code to

document.write("<td width='74'><button id='button' type='button' onclick='myfunction(\""+ name + "\")'>click</button></td>")

Rename your variable name to myname, bacause name is a generic property of window and is not writable in the same window.

And replace

onclick='myfunction(\''" + name + "'\')'

With

onclick='myfunction(myname)'

Working example:

var myname = "Mathew";
document.write('<button id="button" type="button" onclick="myfunction(myname);">click</button>');
function myfunction(name) {
    alert(name);
}