why can't i delete a row in table from javascript?

I'm trying to build a table out from JavaScript, so far so good. The main idea is that the last column will be a checkbox, and when it will be checked the row will delete. before i delete it, i need to know what was written in this row, so i'm checking the id. for some reason it doesn't work. can someone help me? Thanks

this is the building function

 function build(name){

 var myTableDiv = document.getElementById("alertsDiv");
 var table = document.createElement('TABLE');
 var tr;
 var i, j;


  table.style="width:90%; text-align: center; font-size: 13px; border: 1px solid black; border-collapse: collapse";
  table.id = "tbAlerts";
  var tableBody = document.createElement('TBODY');
  table.appendChild(tableBody);
  tableBody.id = "tbBody";

  //users is an array 
for ( i=0; i< Users.length ; i++){
   tr = document.createElement('TR');
   tr.id = name+" row";
   //alert("this is the tr id: " +tr.id);
   tableBody.appendChild(tr);

   //the time
   td = document.createElement('TD');
   var d = new Date();
   td.appendChild(document.createTextNode( d.getHours() +":"+ d.getMinutes() +":"+ d.getSeconds() ));
   tr.appendChild(td);

   //severity
   td = document.createElement('TD');
   td.appendChild(document.createTextNode("minor"));
   tr.appendChild(td);

   //alert
   var td = document.createElement('TD');
   td.appendChild(document.createTextNode(name + " is dead"));
   tr.appendChild(td);

   //comments
   td = document.createElement('TD');
   var txtBox = document.createElement('INPUT');
       txtBox.type = 'text';
       txtBox.placeholder="comments";
   td.appendChild(txtBox);
   tr.appendChild(td);

   //Acknowledge - ***THIS IS THE IMPORTANT THING***
   td = document.createElement('TD');
   var newCheckBox = document.createElement('INPUT');
       newCheckBox.type = 'checkbox';
       rowsNum++;
       newCheckBox.name=name;
       newCheckBox.addEventListener("CheckboxStateChange", cleanAlert, false);
   td.width='10px';
   td.appendChild(newCheckBox);
   tr.appendChild(td);

 }

myTableDiv.appendChild(table);
       }
}

this is the delete function

function cleanAlert(event){
var checkbox = event.target;
var rowIndex;

rowIndex = document.getElementById(checkbox.name + " row").rowIndex;
document.getElementById("tbAlerts").deleteRow(rowIndex);

}