下面一段css代码，帮我解释一下，什么意思，是做什么用的

.tableContainer{ overflow-x:scroll; width:100%; height:100%; dyn-behavior:expression( onscroll == null? (onscroll = function(){ if(event.srcElement.scrollLeft == event.srcElement.oldScroll) return; var oGridBody = document.getElementById("order_GridBody"); oGridBody.style.width = parseInt(event.srcElement.clientWidth) + event.srcElement.scrollLeft + "px"; event.srcElement.oldScroll == event.srcElement.scrollLeft; }):true, onmousedown == null? (onmousedown = function(){ if(self.currentTH != null) return; var obj = document.elementFromPoint(event.x,event.y); var objL = document.elementFromPoint(event.x - 1,event.y); if(obj.tagName.toLowerCase() == "th") { if(objL.tagName.toLowerCase() == "th") { obj = objL; } if(obj.className == "fixed") return; self.currentX = event.x; self.currentTH = obj.childNodes[0]; self.currentTH.setCapture(); } }):true, onmouseup == null? (onmouseup = function(){ if(self.currentTH != null) { self.currentTH.releaseCapture(); self.currentTH = null; } }):true, onmousemove == null? (onmousemove = function(){ if (CurrentRecordCount == 0){ return; } if(self.currentTH != null) { var width = Math.round(parseInt(self.currentTH.clientWidth) + event.x - self.currentX); if(width < 0) width = 0; var dt = parseInt(self.currentTH.style.width) - width; self.currentTH.style.width = width; __resizeCell(self.currentTH.columnIndex,self.currentTH.style.width); self.currentX = event.x; } }):true, self.__resizeCell == null? (self.__resizeCell = function(idx, width){ var nLen = CurrentRecordCount; // alert(CurrentRecordCount); if (nLen==1){ var cells = document.getElementById("GridBody_Cells"); var rows = cells.childNodes; var cell = rows[0].childNodes[idx].childNodes[0]; var resetPattern = /style=[^尀s尀t尀n]+/; cell.outerHTML = cell.outerHTML.toString().replace(resetPattern, "style=✀width:" +width + "✀"); }else{ for (var i=0;i<nLen;i++) { var cells = eval("C_Column" + idx+ "[" + i + "]"); var resetPattern = /style=[^尀s尀t尀n]+/; cells.outerHTML = cells.outerHTML.toString().replace(resetPattern, "style=✀width:" +width + "✀"); // alert(cells.outerHTML); } } }):true )}