function blank (elementId,tagName,rows,number)
{
if(!document.getElementById || !document.getElementsByTagName) return false;
if(!document.getElementById(elementId) || !document.getElementsByTagName(tagName)) return false;
if(arguments.length < 4) return false;
this.Id = document.getElementById(elementId);
this.Tag = this.Id.getElementsByTagName(tagName);

this.num = this.Tag.length;
this.Irow = rows;
this.n = number;
this.temp = Math.floor(this.num/this.Irow);
this.autoBlank = function(i,status) {
	var parent = this.Tag[i].parentNode;
    if(status) {
		var tr = document.createElement('tr');
		var td = document.createElement('td');
		for (var k=0; k<this.n; k++)
		{
		    var br = document.createElement('br');
			td.appendChild(br);
		}
		tr.appendChild(td);
		parent.insertBefore(tr,this.Tag[i]);
	}
	else {
	    for(var k=0; k<this.n; k++) {
        var br = document.createElement('br');
        parent.insertBefore(br,this.Tag[i]);		
        }
	}
}
 
if (this.Tag[0].nodeName == 'TR') {
    for (var j=1; j<=this.temp; j++) {
        var c = j*this.Irow;
	    var i = c+j-1;
	    if(this.Tag[i])
	    this.autoBlank(i,true)
    } 
}

else {
    for (var j=1; j<=this.temp; j++) {
        var i = j*this.Irow;
        if(this.Tag[i])
        this.autoBlank(i,false);
    }
}

}