aspx:
function ChangeFont() {
var selectTags = document.getElementById("DropDownList1");
var fontValue = "";
for (i = 0; i < selectTags.length; i++) {
// Returns the index of the selected option
whichSelected = selectTags[i].selectedIndex;
// Returns the selected options values
fontValue += selectTags[i].options[whichSelected].text + " ";
}
var anchor = document.getElementById("TextBox1");
anchor.style.font = fontValue;
}
font-style:
AutoPostBack="true" OnSelectedIndexChanged="ChangeFont();">