css how to auto size input box code example

Example 1: input width autosize

<input 	id="txt" 
		type="text" 
        onkeypress="this.style.width = (this.value.length + 1) + 'em';">

Example 2: autosize input css

onkeypress="this.style.width = (this.value.length + 1) + 'em';"