Setting the Column Heading

I am trying to set the width and caption of the column heading when initializing for the 1st time
This is the code I used but it is not working.

			var dhx_sh1 = new dhtmlxSpreadSheet({
				load: "../codebase/php/data.php",
				save: "../codebase/php/data.php",
				parent: "gridobj1",
				icons_path: "../codebase/imgs/icons/",
				autowidth: false,
				autoheight: false,
//				config: "cols:10;rows:25;show_row_numbers:true;show_export_buttons:true",
				config: "cols:3;rows:10;show_row_numbers:true;show_export_buttons:false",
                header: [{
					col: 3, 
					width: 64, 
					label: "D111" 

Can anyone help?

please, have a look at file codebase/dhtmlxspreadsheet.js. You may adjust default column width here:

column_width: 64,

Logic of generating column labels is located in method fillHeader:

fillHeader: function() {
	var cols = [""];
	for (var i = 0; i < this.settings.cols; i++)
		cols.push(this.getColName(i + 1));