var arrayTR = document.getElementsByTagName( "tr" );
re1 = new RegExp( "t_Item", "i" );

for( var i=0; i<arrayTR.length; i++ ) {
  if( arrayTR[i].className.match( re1 ) ) {

    arrayTR[i].onmouseover = function() {
      this.style.backgroundColor = "yellow";
    }

    arrayTR[i].onmouseout = function() {
      this.style.backgroundColor = "white";
    }

  }
}