Ограничение ширины изображений

// returns the HTML-formatted string with images which width
// is bigger, than the max value, specified, replaced with
// <а href="to full image"><img width='maxwidth' height='proportional' src='to full image' /></а>
// the smaller images are left unchanged
function smallDownImages( input, maxImageWidth )
  // searching for images in the source
  var inputLeft = input;
  var output = "";
  while ( true )
  {
    // searching for the img tag start
    var leftI = inputLeft.search( /<img[^>] >/mi );
    // checking, if there is something to do
    if ( leftI < 0 )
    {
      output  = inputLeft;
      break;
    };
    
    // adding the part before the image to the output
    if ( leftI > 0 )
      output  = inputLeft.slice( 0, leftI-1 );
      
    // the part of the input, untreated is:
    inputLeft = inputLeft.slice( leftI );
    
    // searching for the end of the image
    var rightI = inputLeft.search( />/mi );
    // checking, if there is a error in tags
    if ( rightI < 0 )
    {
      output  = inputLeft;
      break;
    };
    
    // obtaining the image tag properties
    var imageTag = inputLeft.slice( 0, rightI 1 );
    var width = parseInt( imageTag.match( /width\s*=\s*[\'\"](\d )/mi )[1] );
    var height = parseInt( imageTag.match( /height\s*=\s*[\'\"](\d )/mi )[1] );
    var src = imageTag.match( /src\s*=\s*[\'\"]([^\'\"] )/mi )[1];
    // scaling, if required
    if ( width > maxImageWidth )
    {
      var scale = 0.5   maxImageWidth / width - 0.5;
      width = Math.floor( scale * width   0.5 );
      height = Math.floor( scale * height   0.5 );
      var imageTag = "<a href=\""   src   "\">"   
        imageTag.replace( /(width\s*=\s*[\'\"])(\d )/mi, "$1"   width )
                .replace( /(height\s*=\s*[\'\"])(\d )/mi, "$1"   height )  
        "";
    };
    // and adding to the output
    output  = imageTag;
    
    // the part of the input, untreated is:
    inputLeft = inputLeft.slice( rightI 1 );
  };
  
  // done
  return output;
}