modify placeholder text

src/txBrowser.js

@@ -24,8 +24,8 @@ module.exports = React.createClass({
 		return (
 		<div>
 			<div><h3>Transaction details</h3></div>
-			<input onChange={this.updateBlockN} type="text" placeholder={this.state.blockNumber}></input>
-			<input onChange={this.updateTxN} type="text" placeholder={this.state.txNumber}></input>
+			<input onChange={this.updateBlockN} type="text" placeholder= {"Block number e.g. : " + this.state.blockNumber}></input>
+			<input onChange={this.updateTxN} type="text" placeholder={"Transaction Number e.g. : " + this.state.txNumber}></input>
 			<button onClick={this.submit}>Get</button>
 		</div>
 		);