How to check if a string contains special character using javascript

Sometimes we need to check if a string contains any special charachter. Ex. name should not contains any special character.

Here is the code for it : 

function IsSpecialChar(strString)
//  check for valid SpecialChar strings
{
    var strValidChars = "<>@!#$%^&*()_+[]{}?:;|'\"\\,./~`-=";
    var strChar;
    var blnResult = true;

    if (strString.length == 0) return false;

    //  test strString consists of valid characters listed above
    for (i = 0; i < strString.length && blnResult == true; i++) {
        strChar = strString.charAt(i);
        if (strValidChars.indexOf(strChar) == -1) {
            blnResult = false;
        }
    }
    return blnResult;
}

Happy Learning......