function openWindow(url, name, width, height, scrollbars) {
	var leftOffset = (screen.width - width) / 2, topOffset = (screen.height - height) / 2
	popup = window.open(url, name,'width='+width+',height='+height+',top='+topOffset+',left='+leftOffset+',menubar=0,alwaysRaised=yes,resizable=no,scrollbars='+scrollbars+',status=0')
}

function html_style(tag) {
	if(document.all) {
		if(document.selection.createRange().text) {
			document.selection.createRange().text = '<'+tag+'>'+document.selection.createRange().text+'</'+tag+'>'
		} else {
			alert("Please select some text.")
		}
	} else {
		var tb = document.getElementById("message")
		var before = tb.value.substring(0, tb.selectionStart)
		var selection = tb.value.substring(tb.selectionStart, tb.selectionEnd)
		var after = tb.value.substring(tb.selectionEnd, tb.value.length)
		
		if(selection != '') {	
			tb.value = before+'<'+tag+'>'+selection+'</'+tag+'>'+after
		} else {
			alert("Please select some text.")
		}
	}
}

function html_link() {
	if(document.all) {
		if(document.selection.createRange().text) {
			var response = prompt("Please enter the link address.","http://")
			if(response) {
				if(response != '' && response != 'http://') {
					if(response.search('http://') == -1) response = 'http://'+response
					document.selection.createRange().text = '<a href="'+response+'">'+document.selection.createRange().text+'</a>'
				}
			}
		} else {
			alert("Please select some text.")
		}
	} else {
		var tb = document.getElementById("message")
		var before = tb.value.substring(0, tb.selectionStart)
		var selection = tb.value.substring(tb.selectionStart, tb.selectionEnd)
		var after = tb.value.substring(tb.selectionEnd, tb.value.length)
		
		if(selection != '') {
			var response = prompt("Please enter the link address.","http://");
			if(response) {
				if(response != '' && response != 'http://') {
					if(response.search('http://') == -1) response = 'http://'+response
					tb.value = before+'<a href="'+response+'">'+selection+'</a>'+after
				}
			}
		} else {
			alert("Please select some text.")
		}
	}
}

function html_image() {
	var response = prompt("Please enter the image address.","http://")
	if(response) {
		if(document.all) {
			document.mainform.message.focus()
			if(response != '' && response != 'http://') {
				if(response.search('http://') == -1) response = 'http://'+response
				document.selection.createRange().text = '<img src="'+response+'" />'
			}
		} else {
			var tb = document.getElementById("message")
			var before = tb.value.substring(0, tb.selectionStart)
			var selection = tb.value.substring(tb.selectionStart, tb.selectionEnd)
			var after = tb.value.substring(tb.selectionEnd, tb.value.length)
			if(response != '' && response != 'http://') {
				if(response.search('http://') == -1) response = 'http://'+response
				tb.value = before+'<img src="'+response+'" />'+after
			}
		}
	}
}