Paste this wikitext in the source editor:

<includeonly><div class="quote" style="width:80%;"><span style="font-size: 28px;color: #FFF;font-family: ceuntry;">'''“'''</span><span style="font-size: 18px;color: #FFF;padding:5px;text-shadow: 0 0 1px black, 0 0 1px black, 0 0 1px black, 0 0 1px black, 0 0 1px black;">''{{{1|ParamName1}}}''</span><span style="font-size: 28px;color: #FFF;font-family: ceuntry;">'''”'''</span>{{#if:{{{2|}}}|<br/><span style="font-size: 18px;color: #FFF;padding: 20px;text-shadow: 0 0 1px black, 0 0 1px black, 0 0 1px black, 0 0 1px black, 0 0 1px black;">''―{{{2|ParamName2}}}}}{{#if:{{{3|}}}|, {{{3|}}}''}}</span></div></includeonly>

<noinclude>{{Documentation}}
<templatedata>
{
	"params": {
		"1": {
			"label": "Put a quote here.",
			"description": "Put any quote for the page here.",
			"example": "[Example1]",
			"type": "line",
			"required": true,
			"suggested": true
		},
		"2": {
			"label": "Who said this or who was the author of this quote?",
			"description": "Basically the person who said this.",
			"example": "[Example2]",
			"type": "content",
			"required": true,
			"suggested": true
		},
		"3": {
			"label": "Source of this quote?",
			"description": "Where did this quote come from?",
			"example": "[Example3]",
			"suggested": true
		},
		"4": {
			"label": "What will be the quote box's width?",
			"example": "\"100%\", \"80%\".",
			"type": "number",
			"suggested": true
		}
	},
	"description": "A quote box."
}
</templatedata>
</noinclude>

P.S:- Replace [Example1], [Example2], and [Example3] with the dialogues of your choice. You can also change the descriptions and labels if you'd like, to fit the theme of your wiki (which may also apply to the background image).