Question

For instance, $1.50, 1.50, £4, 3.4 should be processed successfully. Where as just $ or % or # or !2.4 or &45 should given an alert ( special characters ) .

Code: ( in JS )

 validatePrice : function(price){
        var regexPattern = '^(\\$)\[0-9]+(\.\?[0-9]+)?$';
        if (document.asset_edit_frm.price.value.search(regexPattern)== -1){
            alert('Not a valid currency format ');
            document.asset_edit_frm.price.focus();
            return false;
        }else return true;
    }

Answer 1

This will match the pattern you described.

^(?:\$|\u00A3)?[0-9]+(?:\.(?=[0-9]))?[0-9]*$

By the way, if this is straight JavaScript, define the regex as follows:

var regexPattern = /^(?:\$|\u00a3)?[0-9]+(?:\.(?=[0-9]))?[0-9]*$/;

Note the lack of '