[Snapshot14w25a]Sign2

/setblock ~0 ~1 ~0 minecraft:standing_sign 0 replace {Text1:"{text:\"Hi\",clickEvent:{action:run_command,value:\"/say hi\"}}"}

/setblock ~0 ~1 ~0 minecraft:standing_sign 0 replace {
	Text1:"{
		text:\"Hi\",
		clickEvent:{
			action:run_command,
			value:\"/say hi\"
		}
	}"
}


/setblock ~0 ~1 ~0 minecraft:standing_sign 0 replace {Text1:"{text:\"\",extra:[{text:\"Hi\",clickEvent:{action:run_command,value:\"/say hi\"}}]}"}

/setblock ~0 ~1 ~0 minecraft:standing_sign 0 replace {
	Text1:"{
		text:\"\",
		extra:[
			{
				text:\"Hi\",
				clickEvent:{
					action:run_command,
					value:\"/say hi\"
				}
			}
		]
	}"
}