Programs in JavaScript
6. Program to change color of the text box if empty string submitted.<script> function funup(val) { if(val.length>0) document.getElementById('t1').style.borderColor="silver"; } function fun1() { txt = document.getElementById('t1').value if(txt.length == 0) document.getElementById('t1').style.borderColor = "red" } </script> <input type="text" id="t1" onkeyup="funup(this.value)"> <input type="button" value="Submit" onclick="fun1()">Output :
Father of JavaScript