Or simplyer…
This go in your css
            body {
                position: relative;
                width: 100%;
            }
            .box {
                background-color: #F0F0F0;
                color: #888;
                font-family: Arial, Tahoma, serif;
                font-size: 13px;
            }
            .box p {
                padding: 10px;
            }
            .box span {
                float: left;
                font-size: 26px;
                font-weight: bold;
            }
            div.alt {
                background-color: #CCC;
            }
This simply said that you need this version of jquery. Update yours.
    < script type="text/javascript" src="script/jquery-1.3.2.min.js">< /script>
Create a fluid-grid.js and put the 3.1 and 3.2 code inside.
!!! < /script> at line 7 of 3.1 go at the end of 3.2
        <script type="text/javascript">
            var myFluidGrid = {
                COLNUMBER : 2, // Minimum column number.
                COLMARGIN : 10, // Margin (in pixel) between columns/boxes.
                COLWIDTH : 240, // Fixed width of all columns.
                doLayout : function() {
                    var self = this;
                    var pointer = 0;
                    var arr = [];
                    var columns = Math.max(this.COLNUMBER, parseInt($('body').innerWidth() / (this.COLWIDTH + this.COLMARGIN)));
                    $('.box').css('position', 'absolute').css('width', this.COLWIDTH + 'px');
                    $('.box').each(function() {
                        var tempLeft = (pointer * (self.COLWIDTH + self.COLMARGIN));
                        $(this).css('left', tempLeft + 'px');
                        var tempTop = 0;
                        if (arr[pointer]) { tempTop = arr[pointer];    }
                        $(this).css('top', tempTop + 'px');
                        arr[pointer] = tempTop + $(this).outerHeight() + self.COLMARGIN;
                        pointer++;
                        if (pointer === columns) { pointer = 0; }
                    });
                }
            };
            $(window).ready(function() {
                myFluidGrid.doLayout();
            }).resize(function() {
                myFluidGrid.doLayout();
            });
        
Then copy the Step 1 in your text area. And adjuqst all the values to fit your needs.