Get selected row value using JavaScript

You just need to add an event handler to the radio button when you create it:

...
radio.addEventListener('click', radioButtonClick, false);
...

function radioButtonClick() {
    alert(this.getAttribute('value'));
}

This requires that you set the value of the radio button to your team id, or store it on the radio button (which will be the this inside the event handler) in some other way.

You aren't passing a teamid anywhere, so I assumed the teamid is the index of the looped array.

var generate_table = function()
{
    var body = document.getElementsByTagName("body")[0];
    var tbl = document.createElement("table");
    var tblBody = document.createElement("tbody");
    var teamrecord = "test";
    for (var i = 0; i <  teamrecord.length; i++) {
        var row = document.createElement("tr");

        var cell = document.createElement("td");
        var cell1 = document.createElement("td");
        var cell2 = document.createElement("td");

        var cellText = document.createTextNode("teamrecord");
        var cellId = document.createTextNode("teamid");
        var radio = document.createElement("INPUT");
        radio.setAttribute("type", "radio");
        radio.setAttribute("name", "radio");
        radio.setAttribute('data-team', i); // passing the team id


        cell.appendChild(cellText);
        cell1.appendChild(cellId);
        cell2.appendChild(radio);

        row.appendChild(cell);
        row.appendChild(cell1);
        row.appendChild(cell2);

        tblBody.appendChild(row);
    }
    tbl.appendChild(tblBody);
    body.appendChild(tbl);
}

// add an event listener on a dynamic element, and alert the team id
document.addEventListener('click', function(e) {
  if(e.target && e.target.hasAttribute('data-team')) {
    alert(e.target.getAttribute('data-team'));
  }
});

Just add this line, before appending the radio element:

radio.onclick = function(){alert(this.value}; 

Use:

radio.setAttribute("onclick", "anotherFunction(this)")

And after this function, create anotherFunction():

function anotherFunction(object) {
    alert(object.parentNode.parentNode.firstChild.innerHTML);
}

You have several way to achieve that:

The easiest way I think is to add an attribute 'teamid' to the radio button. Then just listen for click event and get this value back.

radio.setAttribute('teamid', teamid);
radio.addEventListener('click', onRadioClick);

function onRadioClick(domEvent) {
    console.log(domEvent.target.getAttribute('teamid'));
}

For me, it is not the best way, because you need to put some information in the DOM... In my opinion, it would be better to separate the presentation and the data:

var tableData = [
    {teamId: 'someId0', title:'title0', someData:'...' },
    {teamId: 'someId1', title:'title1', someData:'...' },
    {teamId: 'someId2', title:'title2', someData:'...' }
];

for (var i = 0, n = tableData.length ; i < n ; i++) {
    var rowData = tableData[i];

    // Create the row using rowData
    // ...

    radio.setAttribute('teamid', rowData.teamId);
    radio.addEventListener('click', onRadioClick.bind(rowData));

    // ...
}

function onRadioClick(domEvent) {
    // Here this represent data of the row clicked
    console.log(this.teamId);
}

I think it's easier to manage, because all data is JavaScript side... You don't store any data in the DOM... However, both work ;)