I\'m doing form validation. when the form input is incorrect i add a red border to the textbox:
document.getElementById(\"fName\").style.borderColor=\"#FF000
Add an onchange event to your input element:
Javascript:
function fName_Changed(fName) { fName.style.borderColor = (fName.value != 'correct text') ? "#FF0000"; : fName.style.borderColor=""; }